1Reviewing the Literature, AR Guide

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Content: 01-Fink Research.qxd 11/1/2004 11:49 AM Page 1 1Reviewing the Literature Why? For Whom? How? A Reader's Guide Purpose of This Chapter What Is a Research Literature Review? Why Do One? Write Proposals for Funding Write Proposals for Academic Degrees Describe and Explain Current Knowledge to Guide Professional Practice Identify Effective research and development Methods Identify Experts to Help Interpret Existing Literature and Identify Unpublished Sources of Information Identify Funding Sources and Works in Progress Satisfy Personal Curiosity Gaining Control: Experiments and Observations An experimental study An Observational Study Systematic, Explicit, Comprehensive, and Reproducible: Four Key Words Choosing an Online Bibliographic Database Public and Private Online Bibliographic Databases What Exactly Do You Need to Find? How Do You Search for What You Want to Find? Key Words, Descriptors, Identifiers, and the Thesaurus research questions and Key Words The Thesaurus as a Source: When Is Enough Really Enough? Key Words or Thesaurus: Chicken or Egg? 1
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Even More Search Terms: Authors, Titles, Title Words, and Journals and Then Some: Limiting the Search How Do You Ask for Information? Searching With Boolean Operators Pausing During the Search Changing the Course of the Search Supplementing the Online Search Reviewing References in High-Quality Studies Is Everything Worthwhile Published? Bring in the Experts Cautiously Approach the Web Standards for Believing Web Sites Organizing the Research Literature: Building a Virtual Filing Cabinet Summary of Key Points Exercises Online Literature Reviews General References
Purpose of This Chapter This chapter gives an overview of the process of doing research reviews and illustrates how they are used. A main objective of the chapter is to demonstrate how to do online searches of the research literature, using major bibliographic or article databases. The chapter provides guidelines on how to ask specific questions of these databases and how to search for the information, using key words, thesauruses, and Boolean logic. The chapter also discusses methods for supplementing online searches, including manual or hand searches of references lists and guidance from experts. Finally, the chapter concludes with a discussion of organizing and storing literature, using bibliographic or reference software. Research literature reviews have many uses. You find them in proposals for funding and for academic degrees, in research articles, in guidelines for professional and evidence-based practice, and in reports to satisfy personal curiosity. Research reviews are comprehensive and
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easily reproducible. They are different from other more subjective reviews, which tend to be selective and perhaps misleading. Research reviewers are explicit about their research questions, search strategy, inclusion and exclusion criteria, data extraction methods, standards for evaluating study quality, and techniques for synthesizing and analyzing their findings. Subjective reviewers choose articles without justifying why they are selected, and they may give equal credence to good and poor studies. The results of subjective reviews are often based on a partial examination of the available literature, and the findings may be inaccurate or even false. Figure 1.1 (see p. 4) shows the steps involved in conducting a research literature review. This chapter covers the shaded portions of the figure: selecting research questions and bibliographic databases and Web sites, choosing search terms, and asking experts to review your methods.
What Is a Research Literature Review? Why Do One? A research literature review is a systematic, explicit, and reproducible method for identifying, evaluating, and synthesizing the existing body of completed and recorded work produced by researchers, scholars, and practitioners. The scholarship and research on which you base the review comes from individuals in diverse professions, including health, education, psychology, business, finance, law, and social services. A research review bases its conclusions on the original work of scholars and researchers. Focusing on high-quality original research rather than on interpretations of the findings is the only guarantee you have that the results of the review will be under your supervision and accurate. A research literature review can be divided into seven tasks: 1. Selecting research questions. A research question is a precisely stated question that guides the review. 2. Selecting bibliographic or article databases, Web sites, and other sources. A bibliographic database is a collection of articles,
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Select Research Questions
Select Bibliographic Databases and Web Sites
Choose Search Terms
Ask Experts to Review Databases and Search Terms
Apply Practical Screen Content covered; years searched; language; setting, sample, interventions, and outcomes studied; research design Apply Methodological Quality Screen Research design; sampling; data collection; interventions; data analysis; results; conclusions Train Reviewers (if more than one) Pilot Test the Reviewing Process
Do the Review Add hand searches of references to online searches
Monitor Quality Ensure reliability and accuracy of review
Synthesize the Results Report on current knowledge; justify the need for research; explain research findings; describe quality of research
Produce Descriptive Review Primarily qualitative synthesis of results
Perform Meta-Analysis Statistical combination of results
Figure 1.1 Steps Involved in Conducting a Research Literature Review
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books, and reports that can provide data to answer research questions. The database is usually accessed online. The bibliographic databases of interest in research reviews contain full reports of original studies. Other sources for literature reviews include the reference lists contained in articles and expert advice. 3. Choosing search terms. Search terms are the words and phrases that you use to get appropriate articles, books, and reports. You base them on the words and concepts that frame the research questions, and you use a particular grammar and logic to conduct the search. 4. Applying practical screening criteria. Preliminary literature searches always yield many articles, but only a few are relevant. You screen the literature to get at the relevant articles by setting criteria for inclusion into and exclusion from the review. Practical screening criteria include factors such as the language in which the article is printed, the setting of a study, and its funding source. 5. Applying methodological screening criteria. Methodological criteria include criteria for evaluating the adequacy of a study's coverage and its scientific quality. 6. Doing the review. Reliable and valid reviews involve using a standardized form for abstracting data from articles, training reviewers (if more than one) to do the abstraction, monitoring the quality of the review, and pilot testing the process. 7. Synthesizing the results. Literature review results may be synthesized descriptively. Descriptive syntheses are interpretations of the review's findings based on the reviewers' experience and the quality and content of the available literature. A special type of synthesis--a meta-analysis--involves the use of statistical methods to combine the results of two or more studies. Why should you do a literature review? You may do one for personal or intellectual reasons or because you need to understand what is currently known about a topic and cannot or do not want to do a study of your own. Practical reasons also exist for doing reviews. Reviews are required, for example, in proposals for grants to do program planning, development, and evaluation. Consider this example.
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Write Proposals for Funding Example. The Fund for Consumer Education is interested in health promotion and disease prevention. One of its current funding priorities is preventing drug and alcohol abuse in older adults. The Community Health Plan decides to apply for a grant from the fund to develop educational materials for the elderly. The fund has specified that all grant proposals include a literature review that proves that the proposed research or education is innovative and evidence based. The Community Health Plan grant writers do a comprehensive literature review. They first search for evidence to support their hypothesis that the risks of alcohol use are different in older and younger people. Numerous research studies provide them with the compelling confirmatory evidence they need. The grant writers also find that currently available educational programs do not adequately make this distinction. Using this information, the Community Health Plan establishes a basis for its proposal to develop, implement, and evaluate an alcohol-use consumer Education Program specifically for people who are 65 years of age and older. The program will use educational methods that the literature suggests are particularly effective in this population. That is, the program will rely on evidence-based educational methods. The fund reviewers agree that the plan grant writers have done a good job of reviewing the literature but ask for more information about the specific educational methods that are being proposed. The plan grant writers expand their literature review to identify methods of learning and instruction that are particularly appropriate for older persons. When writing proposals for funding, you are almost always asked to use the literature to justify the need for your study. You must either prove that nothing or very little can be found in the literature that effectively addresses your study's topic or that the studies that can be identified do not address the topic as well as you will in your proposed
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research. In intervention studies, you will need to provide evidence that the methods you propose to use are likely to be effective. In the preceding example, the proposal writers use the literature to justify their consumer education program by demonstrating that existing materials do not adequately distinguish between the risks of alcohol use in older and younger people. They also use the literature to support their hypothesis that the risks are different and to identify methods of learning and instruction that are specifically pertinent to older people. Literature reviews are also used in proposals for academic degrees.
Write Proposals for Academic Degrees Example. A student in a doctoral program in education plans to write a proposal to prepare a high school curriculum aiming to modify AIDS-related knowledge, beliefs, and self-efficacy related to AIDS preventive actions and involvement in AIDS risk behaviors. The student is told that the proposal will be accepted only if a literature review is conducted that answers these questions: 1. What curricula are currently available? Are they meeting the current needs of high school students for AIDS education? Have they been formally evaluated, and if so, are they effective? 2. What measures of knowledge, beliefs, self-efficacy, and behaviors related to AIDS are available? Are they reliable? Are they valid? The student performs the review and concludes that currently available curricula do not focus on prevention, although some have brief prevention units. The student also finds that valid measures of knowledge, beliefs, and behaviors related to AIDS are available in the literature. Good measures of self-efficacy, however, are not. The student concludes that developing a detailed AIDS prevention curriculum is worthwhile. He plans to use available measures of knowledge, beliefs, and behaviors and will validate a measure of self-efficacy in relation to AIDS preventive actions.
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The student's adviser remains unconvinced by the review. How effective are current curricula in meeting the needs of today's students? Are behaviors more or less risky than a previous generation's? What does the literature say about the prevalence of AIDS among adolescents? The student expands his review of the literature to answer these questions.
Literature reviews are also used to defend current professional practices, as is illustrated in the next example.
Describe and Explain Current Knowledge to Guide Professional Practice Example. A group of physicians reviews the literature to provide a basis for a set of guidelines or recommended practices for treating depressed patients. First, they use the literature to help define depression and the different forms it takes (e.g., major depressive disorder and dysthymic disorder). Next, the physicians rely on the literature for data on effective treatments. They find that the literature supports distinguishing among treatments for different populations of depressed patients (such as children and the elderly), types of depression, gender, and methods of treatment (including medication and psychotherapy). Using the literature review's results, the physicians divide the guidelines into separate categories for each different population of concern and base their recommendations for treatment on gender and type of depression. For example, the recommendations suggest that the treatment for elderly patients with major depressive disorder may be different from the treatment for major depressive disorder in younger patients; treatment for each type of depression, regardless of age, may differ for males and females.
Increasingly, practitioners in occupations such as health and medicine, education, psychology, and social welfare are required to base
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their activities and programs on demonstrably effective practices. For example, suppose a school district wanted to implement a new reading program. Before it could do so, the district would have to provide proof that the new program "worked." If resources are available, the district can conduct a research study to demonstrate the reading program's effectiveness among its students. Another option is for the district to find evidence of effectiveness in the literature. Practices, interventions, programs, and policies that have proof of effectiveness are said to be evidence-based. In the preceding example, the literature review is used in selecting definitions, organizing the guidelines for depression, and linking treatment to type of depression, gender, and age. The literature also can be used to identify methods of doing research or developing and implementing programs, as shown in this example.
Identify Effective Research and Development Methods Example. A review of the literature reveals a validated computerassisted assessment of alcohol use. The assessment has been used with people 65 years of age and older and measures alcohol consumption alone and also in combination with diminished health, medical conditions, and functional status. The writers of a proposal to develop and evaluate an alcohol-use curriculum plan to purchase the computer assessment instrument for their study because the cost of purchasing the instrument is less than the costs of developing and validating a new one. Identifying and using an existing instrument will make the proposal more competitive.
Why reinvent the wheel? A great deal of work has gone into producing methods and instruments that can be adapted to meet your specific needs. For instance, if you are interested in assessing customer or patient satisfaction; health status; or educational knowledge, attitudes, or behavior, the literature is filled with examples for you to copy.
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A literature review may produce conflicting or ambiguous results or may not adequately cover a topic. Experts--persons who are knowledgeable and prominent--are often called in to help resolve the uncertainty that arises when data are inconclusive or missing, as illustrated next.
Identify Experts to Help Interpret Existing Literature and Identify Unpublished Sources of Information Example. After reviewing the literature, three people were found who had published five or more studies on the topic and who also worked in our city. Two agreed to consult with our project and helped us identify other publications of interest. Example. A review of the literature on depression left many questions unanswered. For example, the long-term effects of certain medications were not investigated adequately in the literature, nor was the effectiveness of certain types of "talking therapy." A panel of physicians, nurses, and psychiatric social workers was convened. The panel was asked to supplement the review of the literature with their clinical and other expertise. A major criterion in selecting members of the panel was their publication record as revealed in the literature review.
The literature can also be used to help you find out where to get support for your research. You can also learn about the type of studies being done at the present time. Following is an example of these uses.
Identify Funding Sources and Works in Progress Example. We found 100 relevant studies through our literature search. The National Cancer Institute (NCI) funded about half of them. We contacted the NCI to ask if we could place our name on their list for future studies. We contacted the project
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managers of current projects for as-yet unpublished information to supplement our literature review.
As consumers of health care, education, and social services, we want to make certain that we receive the best services and treatment. The literature can help in this regard by providing access to evaluated programs and helping us to select criteria to do our own assessments. Also, sometimes we are simply curious about an issue, and knowing how to do a literature review can help satisfy our curiosity.
Satisfy Personal Curiosity Example. Voters are being asked to make decisions on the merits of school vouchers. These vouchers are given to parents who can use them to enroll their children in any school of their choosing. The idea is that schools whose performance is currently relatively low will have to do better to "sell" themselves to students. Do school vouchers encourage competition? How do increased choices affect children's intellectual and social well-being? A literature review can be useful in answering questions like these. Example. Some parents have observed that their children appear restless or even agitated after eating very sugary foods. Does eating "too much" sugar induce aggressive behavior in children? A literature review will help you answer this question.
Look at these three case studies. Select the literature review(s). Three Case Studies: Literature Review or Not? Case 1: Policy Making and Program Planning: State-of-the-Art Knowledge The Department of Human Services is considering the adoption of a program of family preservation services. These programs aim
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to prevent children who are at risk for abuse and neglect from being taken from their families. Program participants--families and children--receive emotional, educational, and financial support. Family preservation programs are considered by many practitioners to be worthwhile. Others are not so sure and ask: "Are all equally effective, or are some programs more effective than others?" "If some are more effective, which of their activities makes them more effective?" "Would such activities be appropriate for implementation by the department?" "If the department decides to adopt or adapt an existing family preservation program, what methods and criteria should be used subsequently to evaluate its outcomes and effectiveness?" "Who are the experts in the family preservation field who might be consulted to help with the evaluation?" The department asks for a literature review to get the answers to these questions. The Research Division goes online using three bibliographic databases dealing with social and psychological studies. They identify 200 studies regarding family preservation programs. After evaluating the relevance of the investigators' findings to the needs of the community, they answer the department's questions. Case 2: Preparing Guidelines for Treating Infections and Fever in Nursing Homes Infections are a major cause of morbidity and mortality and a leading cause of hospitalization for nursing home residents. Each year, over 1.5 million infections occur in the institutional long-term care setting. Among elderly nursing home residents, the overwhelming majority of fever episodes are caused by serious infection, which, if inappropriately treated, may result in unnecessary morbidity, mortality, and expenditures. Despite the magnitude of this problem, guidelines for detecting and treating fever in nursing homes are not readily available. To remedy this deficiency, Atlantic Health Care convened a panel of experts, each of whom had published extensively on the subjects of fever, infectious disease, the elderly, and nursing home care. The panelists were asked to distribute their published and unpublished
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research studies before the meeting to facilitate discussion and consensus. Nurses and physicians used a validated "expert panel group process method" to develop practice guidelines for the detection and treatment of fever. The panel also helped to set standards for evaluating quality of care. Both the guidelines and the qualityof-care methods were based on the findings of the panelists' research and their own experience in detecting and treating elderly people with fever. Case 3: What Is Known and Not Known: Justifying the Need for New Studies to Fill in the Gaps Alcohol use in people 65 years of age and older is a growing public health problem. Even if the rate stays the same, doctors and other health professionals can count on seeing an increase in the number of alcoholics, simply because the number of older people in the population will increase. Traditional surveys of alcohol use focus on issues pertaining to young people, such as work and family matters. Very few surveys are available that take into account the concerns of older adults. Alcohol use in older people can impair function, cause or exacerbate illness, or increase the difficulty of treatment. Alcohol also interacts with over 100 of the medications most commonly used by older persons. Finally, older people metabolize alcohol differently from younger people and may suffer adverse effects with relatively few drinks. To address the special needs of older adults, public health workers conducted a literature review to find methods for physicians and other health workers to use in identifying older persons who are at risk for alcohol-related problems or who already have them. The reviewers first went to experts in the field of geriatric medicine and alcohol abuse research and asked for a list of studies they considered to be important. The reviewers examined those studies the experts recommended as well as the references contained within them. Finally, they did an online search of two major medical bibliographic databases to make certain they included all relevant data in their review.
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The review revealed that comparatively little research has focused specifically on older people and that no validated method of measuring alcohol consumption is available for their use in health settings. A main finding of the review was that more research is needed to identify methods for detecting risks for alcohol misuse in this growing segment of society. Cases 1 and 3 use formal literature reviews. In Case 1, the Department of Health and Human Services is planning to depend on the literature to answer all its questions. Consultants will be called in later to help with the evaluation, but they will be identified by studying the literature to determine who they are. In Case 3, the literature review is done to justify research into methods for detecting risks for alcohol misuse in the elderly; no experts are consulted. In Case 2, experts select any studies they consider pertinent. Although literature is certainly used in this scenario, how it is used and its characteristics are not discussed. Are the study results synthesized? Are opinions (e.g., editorials and tutorials) included? Do the studies represent all or a meaningful sample of the available literature? Without answers to questions like these, we cannot really call Case 2 a true literature review. Gaining Control: Experiments and Observations Reviewing the research literature means identifying and interpreting what is known about a topic. High-quality literature reviews base their findings on the evidence from controlled experimentation and observation. They rely on the researcher's original studies for information rather than on other people's interpretations of the results. Editorials and testimonials are usually excluded from the review itself because they are subjective and prone to bias. They are not ignored, however. Expert views--when they come from credible sources--may be used to help interpret findings and answer questions such as these: What references should I include in the review? Have I included all the important references? Why do the findings of some studies contradict the findings of others? To evaluate the research literature, you must learn some basic criteria for evaluating the quality of research. Not all research is
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equally good, and the reviewer must be able to distinguish high- from low-quality research. The objective of high-quality research is to produce accurate information. If your review is based on research that is less than high quality, the results will be less than accurate. High-quality experimental and observational studies, the "gold standards" for systematic reviews, are characterized by study designs that have clearly formulated research objectives and questions, rigorous research plans, valid data collection, and exacting data analysis and interpretation. In an experimental study, the investigator actively intervenes and examines effects. In an observational study, the investigator takes a relatively passive role in observing events. Following are examples of experiments and observations.
An Experimental Study Research Question. How effective is a school-based intervention for reducing children's symptoms of depression and posttraumatic stress disorder resulting from witnessing or being personally exposed to violence? Some children who witness violence develop symptoms of depression or posttraumatic stress disorder (PTSD). Trained school-based mental health researchers used validated measures of depression and PTSD to assess sixth-grade students at two large schools. Sixty-one of 126 students with these symptoms who reported witnessing violence were randomly assigned to a standardized therapy program, and 65 were assigned to a waiting list. Students in the therapy program were tested before their participation and 3 months after it. The researchers found that when compared with the waiting list students, after 3 months of intervention, students who were in the program had significantly lower depression and PTSD scores. But at 6 months, after both groups had received the program, the differences disappeared. The researchers concluded that the program was effective and could be delivered on school campuses by trained school-based mental health personnel.
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An Observational Study Research Question. Who is at greatest risk for melanoma, the deadliest form of skin cancer? To answer this question, researchers conducted a study in which 452 women who had melanoma were compared with 900 women from the general population who did not. The women lived in 5 counties that make up a major American city. All women were interviewed using a standardized interview schedule and highly trained interviewers. The interviewers asked about the women's history of exposure to the sun, medical history, and demographics (such as age). A statistical expert from the local university analyzed the data from the interviews. The researchers found that risk of melanoma increased with increasing tendency to get sunburned, with increased severity and or frequency of sunburns up to age 12, and with lack of use of sunscreen. The first study is an experimental study because the researchers are relatively in charge of the main events. In their study, they administer therapy to reduce symptoms of depression and PTSD in children. The researchers also evaluate the effects of the therapy by creating an experimental group and a waiting list from the same sample, selecting the methods for assigning students to groups, and choosing measures to record changes over time. In contrast, the researchers in the second study do not provide treatment, have no role in assigning people to the group being observed (people with melanoma), and are dependent on people's recall of their past sun exposure and use of sunscreen. Because of the greater methodological control over events that experimenters have compared with observers, experimental studies are generally preferred to observational research. Only well-done studies belong in a literature review. Evaluating the rigor of a study's design is an essential feature of any valid literature review. Only good study designs produce good data.
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Systematic, Explicit, Comprehensive, and Reproducible: Four Key Words Research literature reviews can be contrasted with more subjective examinations of recorded information. When doing a research review, you systematically examine all sources and describe and justify what you have done. This enables someone else to reproduce your methods and to determine objectively whether or not to accept the results of the review. In contrast, subjective reviews tend to be idiosyncratic. Subjective reviewers choose articles without justifying why they are selected, and they may give equal credence to good and poor studies. The results of subjective reviews are often based on a partial examination of the available literature, and their findings may be inaccurate or even false. Subjective reviews should be distinguished from narrative reviews. Narratives may be appropriate for describing the history or development of a problem and its solution. How can you produce a systematic, explicit, comprehensive, and reproducible review? You need to identify precisely what you need to know and decide on the best sources of information. You must also evaluate the quality of the information you find and synthesize the results. This chapter discusses where to go for information and how to ask for it. The next chapters tell you how to justify your choice of studies to review, abstract information from the studies, and analyze and synthesize the results.
Choosing an Online Bibliographic Database Reviews of the literature depend on data from five main sources: (a) online public bibliographic databases (e.g., MEDLINE, PsycINFO); (b) private bibliographic databases (e.g., NexisLexisTM, CINAHL®, EMBASESM); (c) specialized bibliographic databases (Cochrane database of systematic reviews; government reports; and collections maintained by professionals in law, business, and the environment); (d) manual or hand searches of the references in articles; and (e) expert guidance. Remember: The databases relevant to literature reviews are those that contain articles or studies. They are called bibliographic or articles databases.
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Public and Private Online Bibliographic Databases Everyone with an Internet connection has free access to the world's scientific, social scientific, technological, artistic, and medical literature, thanks to the U.S. government that supports it, the scientific community that produces it, and the schools and public and private libraries that purchase access to bibliographic databases and other sources of information. The U.S. National Library of Medicine at the National Institutes of Health, for example, maintains the best site for published medical and molecular biology research. This site is called MEDLINE/PubMed, and access is free from any computer with an Internet connection. All original studies included in MEDLINE (with or without the National Center for Biotechnology Information [NCBI], also known as PubMed) include structured abstracts of each study's objectives, design, and conclusions; many studies are also available in their entirety. To get to MEDLINE, go to www.nlm.nih.gov and click on "Health Information." Another option is to go to the U.S. government's Web site (www.FirstGov.gov) and click on "Health" under "Information by Topic." This site also directs you to other databases, including ERIC, or the Educational Resources Information Center (click on "Education and Jobs" and then on "Student & Teacher Resources"). The National Library of Education (www.ed.gov/NLE) maintains ERIC. If you forget these URLs, go to any search engine and enter MEDLINE or ERIC. University and other libraries, including public libraries, usually provide free access to hundreds of government and nongovernment, private bibliographic databases. A short list of available databases is given below to give you an idea of the range available.
Online Bibliographic Databases: A Small Sample AIDSLINE Anthropological Literature BioethicsLine CANCERLIT
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Current Contents Dissertation Abstracts Educational Resources Information Center (ERIC) EMBASE EconLit GeroLit HealthSTAR Index to Scientific & Technical Proceedings MEDLINE PsycINFO PsycLit SCI Science Citation Index SocioFile Sociological Abstracts TOXLINE
How does the reviewer determine which online databases may be relevant in reviewing a particular research topic? Some, such as PsycINFO or MEDLINE, have names that describe their content (psychology and medicine, respectively). Other articles databases, such as TOXLINE (studies of air pollution and the biological and adverse effects of drugs among other things) or EMBASE (pharmaceutical literature), have names that are not obvious. You need to check out the databases whose names are not familiar to you. Each library usually has a list of databases by subject areas, such as psychology or medicine. If you are unsure about the contents of a specific database, ask a librarian for information, or go directly to the site to find out what topics and resources it includes. If you go to www.csa.com (the URL for Cambridge Scientific Abstracts), you can find an explanation of some commonly used databases in a wide
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variety of fields from agriculture to psychology. The site itself is proprietary in that you have to pay for full use of its services (although your school or workplace might subscribe to it), but the explanation of each database provided by CSA is free. The listing on the site is not, however, a complete compendium of the world's databases, but only those available through CSA. How do you select among bibliographic databases? It all depends on the topic and research questions. For example, if you are interested in finding out what the literature has to say about the best way to teach reading to young children, then the literature in education is clearly an appropriate place to start. However, if you are interested in finding out about interactive reading programs, then a computer and Information Technology database may also be relevant. It helps to be precise about what you want and need to know so you can choose all relevant databases.
What Exactly Do You Need to Find? We have almost instantaneous and worldwide access to research on practically any topic one can think of. Most literature reviews are limited in purpose and time, however. To ensure that you get the literature that you need, and not just an unlimited number of somewhat related (and sometimes unrelated) articles, you must be precise about your research needs. Systematic literature reviews start with very specific needs for knowledge or research questions. Examine these examples of three relatively nonspecific and specific questions:
Examples of Nonspecific and Specific Research Questions Topic 1: Family Preservation Less specific Research Question A. Which programs successfully keep families together?
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More specific Research Question B. Which family preservation programs effec- tively prevent children from being placed out-of-home? Comment Question B is more specific because it describes what it means by the term programs--family preservation programs. Question B also defines what the questioner means by "successfully keeping families together"--keeping children from being placed outof-home.
Topic 2: Curing the Common Cold Less specific Research Question A. What can people do to cure a cold? More specific Research Question B. Can antibiotics cure the common cold? Comment Question B is more specific than A because the vague word do is defined in B as meaning a definite action--taking antibiotics. This clarification may spare you from getting articles about antibiotics and temperature changes, if you use "antibiotics" AND "cold" as key words in your search. (See below for an explanation of the concept of key words.) Topic 3: Alcohol, Women, and breast cancer Less specific Research Question A. How does alcohol use affect breast cancer?
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More specific Research Question B. What is the relationship between drinking two or more alcoholic beverages daily in women 65 years of age and older and breast cancer? Comment Question B is more specific because "alcohol use" is clarified to mean "two or more alcoholic beverages daily," and the targeted population of interest is specified to be women who are 65 years of age and older.
How Do You Search for What You Want to Find? Key Words, Descriptors, Identifiers, and the Thesaurus Research Questions and Key Words A precisely stated research question has the benefit of containing the words the reviewer needs to search online for applicable studies. These words or search terms are often referred to as key words, descriptors, or identifiers. Consider this question (Research Question 1B above): Which family preservation programs effectively prevent children from being placed out-of-home? From the question, you can see that the important words--key words--include "family preservation programs," "children," and "out-of-home placement." What are the key words for Question 2B (above): Can antibiotics cure the common cold? Answer: antibiotics, common cold, cure What are the key words for Question 3B (above): What is the relationship between drinking two or more alcoholic beverages daily in women 65 years of age and older and breast cancer? Answer: women 65 years of age and older, breast cancer, alcoholic beverages Just knowing the key words is not always enough, unfortunately. For instance, suppose you are reviewing family preservation studies to find out which programs work best to prevent out-of-home placement.
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You decide to use PsycINFO for your review because it is an online bibliographic database dealing with subjects in psychology. You also search the database using the exact phrase, "out-of-home placement," and are given a list of 195 articles. You find that the articles contain data on "out-of-home placement," but not all pertain to family preservation programs. To narrow your search and reduce the number of irrelevant studies, you decide to combine "out-of-home placement" with "family preservation," and find that your reviewing task is reduced to 31 articles. However, on further investigation, you find that not all the 31 articles include data on effectiveness. You get data on effectiveness from evaluation studies. So you decide to further narrow the search by adding the term "evaluation," and find that the reviewing task is reduced to a mere 7 articles. This seems like a manageable number of articles to review. Are fewer articles always better? Not necessarily. If your search is very narrow, you may miss out on some important ideas. Look at another example. Suppose you are interested in reviewing medical knowledge of the common cold. If you enter the words "common cold" into the MEDLINE database, you are given a list of 2,835 citations! If, however, you ask for "antibiotics" AND "common cold," you get 222 citations. You can refine this search further by asking for "cure" AND "common cold" so that you are referred to 30 citations. The main reason for the reduction in this number is that antibiotics do not cure common colds, and therefore, the words are not necessarily included as links to the citations for the 222 references that actually do address the issue of colds and cures. The moral of the story is that to get the information you need from the literature, you must balance very specific research questions with justifiable limits or restrictions. One way to achieve a balance between specificity and restriction is to check your planned search terms with those used by authors of articles you trust. Did you include all the terms in your search that they included? All online citations include search terms. Table 1.1 gives an example of a modified citation for an article on family preservation from a search of PsycINFO. The citation includes identifiers and descriptors. Descriptors are terms used by PsycINFO as part of its bibliographic indexing system or thesaurus.
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Table 1.1
A Modified Record From PsycINFO for One Article on Family Preservation
This record was found in: PsycINFO (1840-Current)
Next
View Marked Records Return to Results
1 of 231
UC -eLinks
TI: Title
Why special populations are not the target of family preservation services: A case
for program reform
AU: Author
Denby, Ramona W; Curtis, Carla M
AF: Author Affiliation
University of Nevada Las Vegas, School of Social Work, Las Vegas, NV, US
[Denby]; The Ohio State University, College of Social Work, Columbus, OH, US
[Curtis]
SO: Source
Journal of Sociology & Social Welfare. Vol 30(2), Jun 2003, pp. 149-173
PB: Publisher
US: Western Michigan Univ, http://www.wmich.edu/hhs/Newslettersjournals
AB: Abstract
The number of children who have been placed outside their homes of origin as a
result of abuse, neglect, delinquency, emotional problems, or developmental
disabilities, is astronomical and steadily increasing. Of this number, "special
populations" like children of color continue to be disproportionately represented.
Intensive family preservation, a program that attempts to reduce out-of-home
placement rates, has not demonstrated empirically, a sustained record of success in
the reduction of placement rates among special populations. The purpose of the
current study was to understand the manner in which special populations are
targeted for services by examining the attitudes, beliefs, and behaviors of a national
sample of family preservation workers. Results indicate a significant bias against
targeting family preservation services to special populations in general, and
children of color in particular. Specific recommendations about the targeting of
special populations are given. (PsycINFO Database Record (c) 2003 APA, all rights
reserved) (journal abstract)
LA: Language
English
PY: Publication Year
2003
PT: Publication Type
Peer Reviewed Journal; Empirical Study; Journal Article
PO: Population
Human; Male; Female; Adulthood (18 yrs & older); Young Adulthood (18-29 yrs);
Thirties (30-39 yrs); Middle Age (40-64 yrs)
LO: Location
US
DE: Descriptors
*Attitudes; *Child Welfare; *Community Welfare Services; *Protective Services;
Family; Foster Care
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ID: Identifiers family preservation services; special populations
CL: Classification 3373 Community & Social Services NR: Number of References 67 reference(s) present, 67 reference(s) displayed (omitted from this table)
Next
View Marked Records Return to Results
NOTE: This record was modified from PsycINFO and used with permission of the American Psychological Association, published on the PsycINFO database © 2004, all rights reserved.
Just going to the citation for one important reference can help you greatly in your search. You can use the same descriptors and identifiers as in the reference. If you click on any of the descriptors, you will be directed to articles that cover those topics, which may provide you with additional key words or descriptors. The Thesaurus as a Source: When Is Enough Really Enough? One major source of search terms is a database's thesaurus or dictionary for indexing articles. In the case of PsycINFO, the indexing system is through descriptors. In MEDLINE, it is defined by the Medical Subjects Headings, or MeSH database. The thesaurus is a controlled vocabulary that provides a consistent way to retrieve information across fields that may use different terms for the same concept. For instance, in studies of alcohol, investigators may refer to alcohol abuse as alcoholism, problem drinking, alcohol misuse, substance abuse, and so on. Each database's librarian assigns articles to categories that meet the system's requirements regardless of the investigator's preferences. For instance, suppose you are interested in finding out about alcohol misuse but you want to be certain that you get all articles about misuse, no matter what the investigators call it. Suppose also that you decide to start your search with the database, Sociological Abstracts. As with most databases, Sociological Abstract's home screen will ask if you want to search the thesaurus. If you respond yes by typing in
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"alcohol," you will be given a list of the closest terms, in this case "alcohol abuse." If you click on alcohol abuse, you get an additional listing of terms (Table 1.2). Each term listed in Table 1.2 is searchable. Remember! Thesauruses vary from database to database so check out each one.
Key Words or Thesaurus: Chicken or Egg? A comprehensive search strategy probably requires combining key words and thesaurus terms. If you are certain of your research questions and the variables of interest, a key word search usually produces a relatively narrow range of articles. A search that begins with official thesaurus terms will produce a wide range of articles, but breadth is important if you want your review to be comprehensive. In some fields, such as medicine, evidence exists that using thesaurus terms produces more of the available citations than does reliance on key words. For example, if a reviewer performs a MEDLINE search using the word "hyperlipidemia" but an author has used the narrower term "hypercholesterolemia," then many relevant citations may be missed because only those articles with the word hyperlipidemia in their title or abstract will be retrieved. Using the appropriate subject heading will enable the reviewer to find all citations regardless of how the author uses the term.
Even More Search Terms: Authors, Titles, Title Words, and Journals and Then Some--Limiting the Search You can search for studies by asking for specific authors, titles of articles, words that you expect to be in the title (perhaps you forgot the exact title), and journals. Sometimes this is a useful way to identify key words and thesaurus terms. For instance, suppose you want to find out about programs to prevent child abuse. Asking for the thesaurus headings or key words from an article by any leading researcher in the field will enable you to conduct your search knowing that you are using commonly accepted terms. Searching by specifics--authors, titles--also limits or narrows your search. This can be especially useful if you are not doing an inclusive review. Other methods of narrowing the search include type of
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Table 1.2 Thesaurus From Sociological Abstracts
Alcohol Abuse (D022700) Overuse or misuse of alcoholic beverages. Do not confuse with Alcoholism. Added, 1989. Broader Terms Substance Abuse (D840600) [+] Formerly (1984-1985) DC 450616. Related Terms Addiction (D007350) [+] Added, 1999. Formerly (1963-1985) DC 013500, Addict/Addicts/Addicted/Addictive/Addiction. Alcoholism (D023400) Formerly (1963-1985) DC 027000, Alcoholic/Alcoholics/Alcoholism. Comorbidity (D157400) Coexistence of two or more diagnosable conditions. Added, 2003. Drinking Behavior (D231000) Use limited to drinking alcoholic beverages. Added, 1986. Drug Abuse (D231600) [+] Formerly (1982-1985) DC 140497, Drug Abuse/Drug Abuser/Drug Abusers. Drunkenness (D233400) Formerly (1967-1985) DC 141050. Relapse (D703100) Persistence of Addiction or Substance Abuse, or recurrence of mental illness or other Behavior Problems, especially following Treatment or Rehabilitation. For repetition of criminal or delinquent behavior, see Recidivism. Reinstated, 1999. Formerly (1986-1998) see D696000 Recidivism; (1964-1985) DC 382470. Previous Term: Alcohol Next Term: Alcohol Dependency
Find: Alcohol Abuse Thesaurus
Rotated Index
Display Alphabetical
NOTE: The full name of the thesaurus is Thesaurus of Sociological Indexing Terms. It is used as the indexing authority for Sociological Abstracts and Social Services Abstracts. The presentation and functionality varies according to print versus electronic versions, and across the various search platforms a researcher might be using. The reproduction used here is the version of the thesaurus found on the Cambridge Scientific Abstract Internet Database Service platform.
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publication (e.g., clinical trials, randomized trials), age groups (e.g., infants, adolescents, adults), language, date of publication, and whether the subjects of the study are male or female. Most bibliographic databases facilitate your work by providing menus of commonly used terms. For example, suppose you want to review the literature on women who are 65 years of age and older who drink alcohol because you are interested in alcohol's effects on breast cancer. MEDLINE will let you "limit" the search by providing you with options for the type of study design you want to review, in what languages, and for which ages or gender. Table 1.3 illustrates how this search appears in MEDLINE, and Table 1.4 illustrates how the same search (minus the results) appears in another database, PsycINFO. Note that the search for alcohol has an "*" after it. This symbol is shorthand so that the program searches for alcohol, alcoholism, and alcoholic.
How Do You Ask for Information? Searching With Boolean Operators Literature review searches often mean combining key words and other terms with words such as and, or, and not. These three words are called Boolean operators. Look at these three examples of the use of Boolean logic.
Three Examples of Boolean Logic Example 1: AND "common cold" AND "antibiotics": Use AND to retrieve a set of citations in which each citation contains all search terms. The terms can appear in any order--antibiotics may appear before common cold. Example 2: OR "zinc" OR "Vitamin C": Use OR to retrieve citations that contain one of the specified terms. Example 3: NOT "antibiotics" NOT "children": Use NOT to exclude terms from your search.
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Table 1.3
Limiting Search Strategy for Studies on Alcohol, the Elderly, and Breast Cancer: MEDLINE
Entrez Search
PubMed PubMed
Nucleotide
Protein
Genome
Structure
PMC
for alcohol* AND breast neoplasm OR breast cance
Journals
Books
Limits
Preview/Index
History
Clipboard
Details
Limits: Aged: 65+ years, Publication Date from 2000 to 2005, only items with abstracts, English, Clinical Trial, Female, Human, MEDLINE
Entrez PubMed PubMed Services
Summary
5 Show:
Items 1-5 of 935
Pub Date 1
Text of 187 Next
1: Hack TF, Pickles T, Bultz BD, Ruether JD, Weir LM, Degner LF, Mackey JR.
Related Articles, Links
Impact of providing audiotapes of primary adjuvant treatment consultations to women with breast cancer: a multisite, randomized, controlled trial. J Clin Oncol. 2003 Nov 15;21(22):4138-44. PMID: 14615442 [PubMed - indexed for MEDLINE]
Related Resources
2: Moore DH, Donnelly J, McGuire WP, Almadrones Related Articles, Links L, Cella DF, Herzog TJ, Waggoner SE; Gynecologic Oncology Group. Limited access trial using amifostine for protection against cisplatin- and three-hour paclitaxel-induced neurotoxicity: a phase II study of the Gynecologic Oncology Group. J Clin Oncol. 2003 Nov 15;21(22):4207-13. PMID: 14615449 [PubMed - indexed for MEDLINE]
3: Goss PE, Ingle JN, Martino S, Robert NJ, Muss HB, Piccart MJ, Castiglione M, Tu D, Shepherd LE, Pritchard KI, Livingston RB, Davidson NE, Norton L, Perez EA, Abrams JS, Therasse P, Palmer MJ, Pater JL.
Related Articles, Links
A randomized trial of letrozole in postmenopausal women after five years of tamoxifen therapy for early-stage breast cancer. N Engl J Med. 2003 Nov 6;349(19):1793-802. Epub 2003 Oct 09. PMID: 14551341 [PubMed - indexed for MEDLINE]
4: Yoshimoto M, Tada K, Tokudome N, Kutomi G, Tanabe M, Goto T, Nishimura S, Makita M, Kasumi F.
Related Articles, Links
The potential for oral combination chemotherapy of 5'-deoxy5-fluorouridine, a 5-FU prodrug, and cyclophosphamide for metastatic breast cancer. Br J Cancer. 2003 Nov 3;89(9):1627-32. PMID: 14583760 [PubMed - indexed for MEDLINE]
5: Sharma RA, Decatris MP, Santhanam S, Roy R, Related Articles, Links Osman AE, Clarke CB, Khanna S, O'Byrne KJ.
(Continued)
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Table 1.3 (Continued)
Reversibility of liver failure secondary to metastatic breast cancer by vinorelbine and cisplatin chemotherapy. Cancer Chemother Pharmacol. 2003 Nov;52(5):367-70. Epub 2003 Jul 18. PMID: 12879281 [PubMed - indexed for MEDLINE]
Summary
5 Show:
Items 1-5 of 935
Pub Date 1
Text of 187 Next
Write to the Help Desk NCBI | NLM | NIH Department of Health & Human Services Freedom of Information Act | Disclaimer
Table 1.4
Limiting Search Strategy for Studies on Alcohol, the Elderly, and Breast Cancer: PsycINFO
Searching:
PsycINFO (1840-Current)
Build your search strategy Keyw ords (KW=) and Keyw ords (KW=) and Keyw ords (KW=)
( alcohol*
or
( elderly
or
( breast can or
or
)
eg: intellectual propert*
aging
or aged
)
eg: jones or smith
breast neo or
)
Limit To: Only Earliest From citation Show Search
Latest Update
Journal Articles Only
2004 to
publication date Sort by
Clear
English
Search
Clear
Be careful when using NOT because you may inadvertently eliminate important articles. In Example 3, articles about children and antibiotics are eliminated, but so are studies that include children as part of a discussion of antibiotics and all age groups.
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In addition to AND, OR, and NOT an individual concept can be enclosed in parenthesis, and the terms inside the parentheses will be processed as a unit. Table 1.5 presents an efficient method of searching called nesting. The computer will search for any articles on common
Table 1.5 Nesting and Searching
Entrez
PubMed
Search PubMed Limits
Nucleotide
Protein
Genome
Structure
PMC
for common cold AND (vitamin c or zinc)
Preview/Index
History
Clipboard
Journals
Books
Details
Entrez PubMed PubMed Services Related Resources
Summary
5
Sort
Show:
Items 1-5 of 289
Text
1
of 58 Next
1: McElroy BH, Miller SP.
Related Articles, Links
An open-label, single-center, phase IV clinical study of the effectiveness of zinc gluconate glycine lozenges (Cold-Eeze) in reducing the duration and symptoms of the common cold in school-aged subjects. Am J Ther. 2003 Sep-Oct;10(5):324-9. PMID: 12975716 [PubMed - in process]
2: Eby G.
Related Articles, Links
Cold-Eeze lozenge for common colds. Am J Ther. 2003 May-Jun;10(3):233; author reply 233-4. No abstract available. PMID: 12756432 [PubMed - indexed for MEDLINE]
3: Rizkallah G, Seaton T.
Related Articles, Links
Zinc nasal gel effective for the common cold. J Fam Pract. 2003 May;52(5):352-3. No abstract available. PMID: 12737760 [PubMed]
4: Hein MS.
Related Articles, Links
Copper deficiency anemia and nephrosis in zinc-toxicity: a case report. S D J Med. 2003 Apr;56(4):143-7. PMID: 12728841 [PubMed - indexed for MEDLINE]
5: Donma O, Donma MM.
Related Articles, Links
Association of headaches and the metals. Biol Trace Elem Res. 2002 Winter;90(1-3):1-14. Review. PMID: 12666820 [PubMed - indexed for MEDLINE]
Summary
5
Sort
Show:
Items 1-5 of 289
Text
1
of 58 Next
Write to the Help Desk NCBI | NLM | NIH Department of Health & Human Services Freedom of Information Act | Disclaimer
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cold AND zinc or common cold AND Vitamin C. If both Vitamin C and zinc are studied in a single article, the computer will be able identify it, but the computer will not limit its search to just common cold and Vitamin C and also zinc. Not all bibliographic databases require you to capitalize AND, OR, and NOT. Check the "advanced search" function to make certain. Each search engine has its own peculiarities.
Pausing During the Search When your search is no longer fruitful, review your collection of literature. Check the entire list for quality and comprehensiveness. Get assistance from someone who is interested in the topic or has worked in the field. Ask: Are all important investigators or writers included on the list? Have any major studies been excluded?
Changing the Course of the Search You change course by considering new key words, subject headings, authors, and so on. A change in course may expand the scope of your review. Consider this example.
Changing the Course of a Literature Review Search: Expanding the Scope Example. A psychologist reviewed the literature to find out how exposure to radiation affects people's psychological well-being. The review focused on catastrophes such as the Russian nuclear power plant disaster at Chernobyl in 1990. As part of the review, the psychologist discovered that the Chernobyl disaster subsequently affected over 1 million immigrants to the U.S. and Israel. The psychologist expanded the review to consider the implications for policymakers of having to consider the needs of substantial numbers of immigrants who may have special mental health problems resulting from participation in the disaster. This topic appeared especially pertinent given the number of
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immigrants throughout the world who have participated or witnessed wars and other disasters.
Supplementing the Online Search Is the following statement true or false? An experienced literature reviewer needs only access to the Internet to do a comprehensive literature review. The answer is "false." Experienced literature reviewers must know how to locate databases and use the correct language and syntax to identify key words, subjects, titles, and so on to identify pertinent studies. However, search processes are far from uniform or perfect, the databases and study authors may not use search terms uniformly (especially true with new topics), and even the most proficient reviewers may neglect to find one or more studies regardless of how careful they are. In addition, a reviewer may in actuality have access to just a few databases. Also, some studies may be in progress and not yet ready for publication. Finally, some potentially important studies may never get published. The following summarizes the main reasons for supplementing computer searches of the literature with other data sources. Reasons to Supplement Electronic Searches · The topic is new and its associated concepts have not yet been incorporated into official subject headings. · Search terms are used inconsistently because definitions in the field are not uniform. · There is reason to believe that many important studies are in progress or complete but not published. Where do you go when being online is insufficient? Consider the following supplemental sources:
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What to Do When an Online Search Is Insufficient · Review the reference lists in high-quality studies. · Talk to colleagues and other experts. · Review major government, university, and foundation Web sites. Reviewing References in High-Quality Studies Believe it or not, after many, many hours of searching, you may fail to uncover all there is to know about a topic. This can easily happen if you rely on just one or two databases. For instance, if you are interested in the relationship between alcohol use and breast cancer in older women and rely on MEDLINE alone for information, you will get a great deal of clinical information, but you may not retrieve some of the available research on the psychosocial factors associated with alcohol drinking and with breast cancer. If, however, you rely on a database that deals with research on psychosocial variables, such as PsycINFO, you may not obtain some medical or health information. Even if you use both databases, you may fail to uncover some clinical and psychosocial articles. It is unclear why this happens, but it may. One way to avoid missing out on important studies is to review the references in high-quality articles. You do not necessarily need to retrieve the article to do this because some databases (such as PsycINFO and Sociological Abstracts) provide a list of searchable references as part of the citation (if you ask for it). Listen in on this conversation between a frustrated reviewer and a more experienced colleague to get a feeling for how references in articles can help provide coverage for a literature review. Searching the References: A Conversation Between an Experienced and a Frustrated Reviewer Experienced Reviewer (ER): I have been reviewing your list of references and notice that you do not include Monashe's experiment to find out how to teach young adults how to be better consumers.
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Frustrated Reviewer (FR): I did a search of 10 databases and asked specifically for Monashe. How did I miss that study? ER: Very simple. Monashe hasn't published it yet. FR: If Monashe hasn't published it, how could I find it? ER: If you had reviewed the references in my study of education and young adults, you would have found it. I knew that Monashe was working on the study and I asked her to tell me about it. She is currently working on the paper but was able to give me a monograph. She wrote the monograph to fulfill the obligations of the government contract that sponsored the study. The government insists that the monograph be made available at a nominal cost to other researchers. You can download the monograph from www.nixx.cdd.gov FR: I wonder how many other studies I may have missed because I didn't study the references. ER: I wonder, too.
Is Everything Worthwhile Published? Unpublished literature has two basic formats. The first consists of documents (final reports required by funding agencies, for example) that are written and available in print or online--with some detective work-- from governments and foundations. Monashe's monograph discussed in the preceding conversation between the experienced and frustrated reviewers is an example. But some studies do not get published at all. Although some unpublished studies are most certainly terrible or are the products of lazy researchers, some important ones are neither. These studies are not published because their conclusions are unremarkable or even negative, and journals tend to publish research with positive and interesting findings. Much has been written about the effects of failing to publish studies with negative findings. The fear is that because only exciting studies (i.e., those that find that a treatment works, for example) are published, invalid conclusions inevitably result because less provocative studies with negative or contrary findings are not published. That is, if Reading Program A has one positive study and two negative ones, but we only get to know about the positive one, then Program A will look
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more effective than it may be in actuality. This phenomenon--publication of positive findings only--is called publication bias. The general rule in estimating the extent of publication bias is to consider that if the available data uncovered by the review are from highquality studies and reasonably consistent in direction, then the number of opposite findings will have to be extremely large to overturn the results.
Bring in the Experts Experts are individuals who are knowledgeable about the main topic addressed in the literature search. You can find experts by examining the literature to determine who has published extensively on the topic and who is cited often. You can also ask one set of experts to nominate another. Experts can help guide you to unpublished studies and work in progress. They may also help interpret and expand on your review's findings. They help answer questions such as these: Do my literature review findings apply to everyone or to only a particular group of people? How confident can I be in the strength of the evidence? What are the practical or clinical implications of the findings? Following are abstracts of two literature reviews that illustrate the use of experts. The first review is concerned with the risks associated with the treatment of depression in pregnant women. In that review, experts are called in to discuss references identified by reviewers. In the second review, experts are asked for references and books regarding the optimal treatment of urinary tract infections in older women. Their recommendations are supplemented by online searches.
Expert Guidance: How to Use It Literature Review 1: Pharmacologic Treatment of Depression During Pregnancy1 Background Depression is common among women of childbearing age. Even so, not much information is available that can help patients and physicians decide on treatment during pregnancy.
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Objective This study aimed to identify risks associated with treating major depression during pregnancy. Having this information can help physicians come up with plans for treatment. Data Sources The researchers searched MEDLINE and HealthSTAR for 1989 through 1999 using the search terms antidepressant during pregnancy and depression during pregnancy. They also manually searched the references in review articles and had discussions with investigators. To be included, a study had to be reported in English and a prospective controlled trial.
Literature Review 2: Antibiotics for Urinary Tract Infections2 Background Urinary tract infections are common in elderly patients. Authors of nonsystematic literature reviews often recommend longer treatment durations (7­14 days) for older patients than for younger women, but the researchers in this review start with the premise that the scientific evidence for such recommendations is not clear. Objectives The researchers aimed to determine the optimal duration of antibiotic treatment for uncomplicated symptomatic lower urinary tract infections in elderly women. Data Sources The researchers relied on MEDLINE, EMBASE, CINAHL, HealthSTAR, POPLINE, Gerolit, BioethicsLine, the Cochrane Library, Dissertation Abstracts International, and Index to Scientific & Technical Proceedings. They also contacted known investigators and pharmaceutical companies that sell
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antibiotics used to treat urinary tract infections. The researchers screened the reference list of identified articles, reviews, and books.
Cautiously Approach the Web The Internet contains a vast amount of information on just about any topic under the sun. As a source of credible, experimentally derived information, however, it is a mixed blessing. Its greatest advantage is that the world's literature is available to anyone who knows how to get to it. But even experienced reviewers can find themselves confronted with a mass of information of dubious quality, and quality controls for Internet sites are practically impossible to oversee. The Geneva-based Health on the Net Foundation's voluntary set of ethical standards for health Web sites can help consumers discern the veracity of online information, but some say the standards are not always the best way to find reliable health information online. The HONcode, created in 1995 (www.hon.ch), is the oldest and most widely used Internet information code, covering more than 3,500 Web sites based in 67 countries. The HON (Health on the Net Foundation) site also features a search engine for medical information, and results come only from HON-accredited sites. The group accredits sites that abide by a set of eight principles; these sites are then allowed to display the HON code logo. The standards require that information providers reveal potential conflicts of interest, list credentials for authors relaying medical information, and reference their information sources. Administrators of HON say they have trouble keeping up with information on complementary and alternative medicine (CAM) on Web sites, some of which display the HONcode seal but are not accredited. Healthfinder.gov, for example, a health information clearinghouse funded by the U.S. government, includes the HON code and links to more than 1,700 sites, most of which are HON-compliant. The site links to government Web sites, federally funded research centers, and national professional associations of licensed health care practitioners.
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Unfortunately, even with its weaknesses, the HON code is the only one of its kind. Also remember, that in using the Internet, unless you have a specific address that you know will get you the data you need (e.g., http://findlit.com.nih.xxx.edu), you must be prepared to spend time performing detective work. If you just rely on the first page of results from a search engine, you may miss out on the information you really need. Even if your search is precise, you may find hundreds of pages to sort through before you get where you want to go. To add insult to injury, even if you do locate a great site, saving it for future review may be useless because unless the site is stable, it may disappear without warning. Many sites simply vanish. Thus, the Internet is not an efficient source for a comprehensive review of the literature. It is extremely time-consuming to use because all sites and publications must be evaluated carefully. If you do decide to search the Web for literature, make sure you get a satisfactory answer to EACH of the following questions.
Standards for Believing Web Sites · Who supports or funds the site? Does the funder have any financial interest in the outcomes of the study? · When was the site last updated? Are the findings still relevant? · What authority do the authors/investigators have to do the study? Interpret the findings? Do the investigators give sufficient information so that you can evaluate their qualifications? Are the investigators likely to profit from the outcomes of the study? Do the investigators have peer-reviewed publications in good journals?
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· Is the study an experimental or a high-quality observational study? Do the investigators describe what they did, how they did it, and the weaknesses or biases that might be present in their findings?
You should be able to get answers to each of these questions without having to leave the site. If you have any trouble using the site or finding the information you need to answer each question, raise your index of suspicion to its highest level, and leave the site for a better one. Organizing the Research Literature: Building a Virtual Filing Cabinet Articles and abstracts can be stored in several places. You can print out hard copies and file them in a cabinet. The fact is that after most reviews are completed, large numbers of stored paper articles are usually left to disintegrate. An additional storage method focuses on creating reference lists by hand entering titles, authors, and so on in word processing programs, spreadsheets, database manager programs (such as Access), and statistical programs. Hand entry is tedious, however, and prone to error due to typing. Moreover, unless the reference list is short, it is costly to spend time manually entering supplementary information for each article such as the key words or descriptors, abstract, and authors' affiliations. Fortunately, you do not have to hand enter references or store them in steel or wooden file cabinets. Software exists that enables you to store the results of your search in a virtual file cabinet. These programs enable you to download references (including the abstract and URL) from hundreds of online databases. For instance, suppose you ask the software for MEDLINE. You will be automatically connected to that database and asked for titles, or authors, or key words, and so on. Once you supply this information, the computer will generate a list of references. You click on each reference that you want, and the full citation
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is inserted into a library that you create on your computer. The citation includes the abstract and the URL or other links so that you can access the full article (if it is available to you and you are online). You can also hand enter references into the library and download references directly from journals. Suppose you are searching AIDSLINE and find an interesting article. You can download the reference into the virtual file cabinet in your computer by clicking on an instruction such as "download to reference manager." Reference organizers are efficient. They have many features beyond serving as a virtual file cabinet. They provide the means for you to save your search strategy (so that you can continue your search over time and others can use it), insert references from your library directly into reports and scholarly articles, and analyze the references by thematic content. An important reason to use bibliographic software management programs is because they help ensure accuracy and reproducibility. You can easily update a library, e-mail it, and post it on the web.
Summary of Key Points · A literature review is a systematic, explicit, comprehensive, and reproducible method for identifying, evaluating, and interpreting the existing body of original work produced by researchers and scholars. · Literature reviews are used for the following reasons: To write proposals for funding To write proposals for degrees To describe and explain current knowledge to guide professional practice To identify effective research and development methods To identify experts to help interpret existing literature and identify unpublished sources of information To identify funding sources and works in progress To satisfy personal curiosity
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· High-quality literature reviews base their findings on evidence from experiments or controlled observations. · High-quality literature reviews are systematic, explicit, comprehensive, and reproducible. · Online searches usually are the most efficient to start with. To use them effectively, you must have specific questions, key words, identifiers, and/or descriptors and learn to use Boolean logic. · Comprehensive literature reviews mean supplementing the electronic search with reviews of the references in the identified literature, manual searches of references and journals, and consultation with "experts" to learn about unpublished and published studies and reports. · Be wary of the Web as a source of credible research unless you have evidence that a site of interest is stable and unbiased. · Reference management programs provide you with the means to set up virtual file cabinets, and they help ensure accuracy and reproducibility. You can easily update a library and e-mail it to other people who are interested in the same topic.
01-Fink Research.qxd 11/1/2004 11:49 AM Page 43 Exercises 1. You have been asked to design an educational and counseling program for people who are fearful of heights. Your research question is this: What are the determinants of and treatments for adults and older people who have a fear of heights? Before you begin to develop the program, you decide to do a literature review to ensure that the content of the proposed program will be up to date. You decide to use MEDLINE and PsycINFO (or similar databases) for your search. List at least 10 other key words or subject or thesaurus terms that you can use to find out what is currently known about the determinants and treatments for adults who are afraid of heights. 2. You are writing a proposal to do research into the prevention of common colds in adults who are middle-aged and older. Use a medical or health database to do your search. You propose to review only clinical studies in English. Which search terms do you use? How many citations result? 3. The following are sample abstracts retrieved from the MEDLINE and PsycINFO databases for your study of the prevention and spread of common colds. You decide to review the abstract first and then, based on the abstract, you will review only those studies that sound promising. Select the abstracts that are potentially appropriate for your review and justify your selection. Prevention and Control of the Common Cold: Selected Abstracts Abstract 1 Author: Smith, A. P. Title: Respiratory virus infections and performance Source: IN: Human factors in hazardous situations; D. E. Broadbent, J. T. Reason, Alan D. Baddeley, Eds. Clarendon Press/Oxford University Press, Oxford, England, 1990. 71­80 of vii, 147 pp. 43
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In this chapter, the author maintains that minor illnesses, such as colds, and influenza, are frequent, widespread and a major cause of absenteeism from work and education. Because of this, it is important to determine whether these viral infections alter the efficiency with which people perform certain tasks. To find out, the author reviewed studies from the Medical Research Centre Common Cold Unit and found that colds and influenza have selective effects on performance. In fact, the studies that the author reviewed showed that even subclinical infections can produce performance impairments; performance may be impaired during the incubation period of the illness; and performance impairments may still be observed after the clinical symptoms have gone. The author concludes that the findings from these studies have strong implications for occupational safety and efficiency.
Abstract 2
Author: Hemila, H.
Address: Department of Public Health, University of Helsinki, Finland
Title:
Does Vitamin C alleviate the symptoms of the common cold? A review of current evidence
Journal: Scandinavian Journal of infectious diseases, 1994, 26(1):1­6
In this article, the author reviews 21 placebo-controlled studies that have been done to find out if Vitamin C at a dosage of 1 g/day affects the common cold. According to the author, the 21 studies did not provide consistent evidence that Vitamin C supplementation reduces the incidence of the common cold in the general population. However, the author also points out that in each of the 21 studies, Vitamin C reduced the duration of episodes and the severity of the symptoms of the common cold by an average of 23%. Because there have been large variations in the benefits observed, the author notes that clinical significance cannot be clearly inferred from the results.
Abstract 3
Author: Sattar SA; Jacobsen H; Springthorpe VS; Cusack TM; Rubino JR
Title:
Chemical disinfection to interrupt transfer of rhinovirus type from environmental surfaces to hands
Journal: Applied and Environmental Microbiology, 1993 May, 59(5): 1579­85
The researchers in this study point out that rhinoviruses [which cause colds] can survive on environmental surfaces for several hours under ambient
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conditions. Hands can readily become contaminated after contact with such surfaces, and self-inoculation may lead to infection. Whereas washing your hands is crucial in preventing the spread of rhinovirus colds, proper disinfection of environmental surfaces may further reduce rhinovirus transmission. In this study, the authors compared the capacities of Lysol Disinfectant Spray, a bleach, a quaternary ammonium-based product, and a phenol-based product in interrupting the transfer of a type of rhinovirus from stainless steel disks to the finger pads of human volunteers. Among the findings were that the Lysol spray was able to reduce virus infectivity by > 99.99% after a contact of either 1 or 10 min, and no detectable virus was transferred to finger pads from Lysol-treated disks. The bleach reduced the virus titer by 99.7% after a contact time of 10 min, and again no virus was transferred from the disks treated with it.
Abstract 4
Author: Audera C, Patulny RV, Sander BH, Douglas RM
Title:
Mega-dose Vitamin C in treatment of the common cold: A randomised controlled trial
Journal: Med J Aust. 2001 Oct 1, 175(7):359­62
The investigators were interested in studying the effect of large doses of Vitamin C on the treatment of the common cold. They enlisted 400 volunteers to participate in an 18-month double-blind, randomized clinical trial with four intervention arms: Vitamin C at daily doses of 0.03 g ("placebo"), 1 g, 3 g, or 3 g with additives ("Bio-C") taken at onset of a cold and for the following 2 days. They found no significant differences in any measure of cold duration or severity among the four medication groups. The investigators concluded that doses of Vitamin C in excess of 1 g daily taken shortly after onset of a cold did not reduce the duration or severity of cold symptoms in adult volunteers when compared with a Vitamin C dose less than the minimum recommended daily intake.
Abstract 5
Author: Khaw KT; Woodhouse P
Title:
Interrelation of Vitamin C, infection, haemostatic factors, and cardiovascular disease
Journal: BMJ, 1995 Jun 17, 310(6994):1559­63
The two researchers hypothesized that the increase in fibrinogen concentration and respiratory infections in winter is related to seasonal variations in Vitamin C status (assessed with serum ascorbate concentration). To test the hypothesis, they studied 96 people 65 to 74 years at intervals of 2 months
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over 1 year. The investigators found that average dietary intake of Vitamin C varied from winter to summer. They also found that an increase in dietary Vitamin C of 60 mg daily (about one orange) was associated with a decrease in fibrinogen concentrations of 0.15 g/1, equivalent (according to prospective studies) to a decline of approximately 10% in risk of ischaemic heart disease. Based on this and other of their statistical results, the researchers concluded that the study findings support the hypothesis that Vitamin C may protect against cardiovascular disease through an effect on haemostatic factors at least partly through the response to infection.
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ANSWERS 1. Key words and other terms that can be used to find out about adults who are afraid of heights are acrophobia, agoraphobia, altitude, anxiety, anxiety neuroses, arousal, awareness, behavior therapy, benzodiazepines, defense mechanism, desensitization, fear, fear of heights, internal-external control, neuropathy, panic, panic disorder, phobia, phobic disorders (diagnosis), phobic disorders (psychology) physiological correlates, set (psychology), threat, vestibular apparatus. 2. Using MEDLINE, your search will result in 23 citations and look something like this (as of January 2004).
Entrez
PubMed
Nucleotide
Protein
Genome
Structure
Search PubMed
for common cold AND prevention
Limits
Preview/Index
History
Clipboard
PMC
Journals
Details
Books
Text Version Entrez PubMed Overview Help | FAQ Tutorial New/Noteworthy E-Utilities
Limits: Middle Aged + Aged: 45+ years, only items with abstracts, English, Clinical Trial, Female, Human, MEDLINE
Summary
5
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Text
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Items 1­5 of 23
1
of 5 Next
PubMed Services Journals Database MeSH Database Single Citation Matcher Batch Citation Matcher Clinical Queries LinkOut Cubby Related Resources Order Documents NLM Gateway TOXNET Consumer Health Clinical Alerts ClinicalTrials.gov PubMed Central Privacy Policy
1: Van Straten M, Josling P.
Related Articles, Links
Preventing the common cold with a vitamin C supplement: a double-blind, placebo-controlled survey. Adv Ther. 2002 May-Jun;19(3):151­9. PMID: 12201356 [PubMed - indexed for MEDLINE]
2: Audera C, Patulny RV, Sander BH, Douglas RM. Related Articles, Links
Mega-dose vitamin C in treatment of the common cold: a randomised controlled trial. Med J Aust. 2001 Oct 1;175(7):359­62. PMID: 11700812 [PubMed - indexed for MEDLINE]
3: Josling P.
Related Articles, Links
Preventing the common cold with a garlic supplement: a double-blind, placebo-controlled survey. Adv Ther. 2001 Jul-Aug;18(4):189­93. PMID: 11697022 [PubMed - indexed for MEDLINE]
(Continued) 47
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4: Suzuki T, Yanai M, Yamaya M, Satoh-Nakagawa Related Articles, Links T, Sekizawa K, Ishida S, Sasaki H. Erythromycin and common cold in COPD. Chest. 2001 Sep;120(3):730­3. PMID: 11555501 [PubMed - indexed for MEDLINE]
5: Bensenor IM, Cook NR, Lee IM, Chown MJ, Hennekens CH, Buring JE, Manson JE.
Related Articles, Links
Active and passive smoking and risk of colds in women. Ann Epidemiol. 2001 May;11(4):225­31. PMID: 11306340 [PubMed - indexed for MEDLINE]
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Write to the Help Desk NCBI | NLM | NIH Department of Health & Human Services Freedom of Information Act | Disclaimer
3. Abstracts 3, 4, and 5 are experiments and may be useful in the review. Abstract 1's information can be used to help interpret the review's findings. Because it collects no new information, it is not eligible for inclusion into the database that composes a literature review. Abstract 2 is a review of the literature; it may be a useful check on your review's content and conclusions. Online Literature Reviews For outstanding examples of stand alone literature reviews, go to the Cochrane Collaboration's Web site: www.cochrane.org The Cochrane Collaboration is an international nonprofit and independent organization, dedicated to making up-to-date, accurate information about the effects of health care readily available worldwide. It produces and disseminates systematic reviews of health care interventions and promotes the search for evidence in the form of clinical trials and other studies of interventions. The major product of the collaboration is the Cochrane Database of Systematic Reviews, which is published quarterly as part of the
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Cochrane Library. Volunteer health care professionals do the reviews. They work in one of the many collaborative review groups with editorial teams overseeing the preparation and maintenance of the reviews, as well as application of the rigorous quality standards for which Cochrane Reviews have become known. The following is a list of literature reviews available in their entirety online (as of February 2004). They have been selected to illustrate the range of topics, research questions, and research methods used to review the literature using a variety of bibliographic databases and other techniques. Baldwin, R. C., Anderson, D., Black, S., Evans, S., Jones, R., Wilson, K., et al. (2003). Guideline for the management of late-life depression in primary care. International Journal of Geriatric Psychiatry, 18(9), 829­838. (found in MEDLINE and PsycINFO) Cobner, R., & Hill, J. (2003). What works for whom? A critical review of treatments for children and adolescents [Review]. Clinical Child Psychology & Psychiatry, 8(4), 557­559. (found in PsycINFO) Cusick, L. (2002). Youth prostitution: A literature review. Child Abuse Review, 11(4), 230­251. (found in Sociological Abstracts) Dennis, L. K., Beane Freeman, L. E., & VanBeek, M. J. (2003). Sunscreen use and the risk for melanoma: A quantitative review. Annals of Internal Medicine, 139, 966­978. (found in MEDLINE) Joyce, J., Rabe-Hesketh, S., & Wessely, S. (1998). Reviewing the reviews: The example of chronic fatigue syndrome. Journal of the American Medical Association, 280(3), 264­266. (found in MEDLINE) Lutters, M., & Vogt, N. (2003). Antibiotic duration for treating uncomplicated, symptomatic lower urinary tract infections in elderly women (Cochrane Review). The Cochrane Library, Issue 4. (see www.cochrane.org) McDonald, H. P., Garg, A. X., & Haynes, R. B. (2002). Interventions to enhance patient adherence to medication prescriptions: Scientific review [Review]. Journal of the American Medical Association, 288(22), 2868­2879. Erratum in Journal of the American Medical Association (2003), Vol. 289, No. 4, 3242. (found in MEDLINE) Reynolds, K., Lewis, B., Nolen, J. D., Kinney, G. L., Sathya, B., & He, J. (2003). Alcohol consumption and risk of stroke: A meta-analysis. Journal of the American Medical Association, 289(5), 579­588. Erratum in Journal of the American Medical Association (2003), Vol. 289, No. 21, 2798. (found in MEDLINE)
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Rottinghaus, P. J., Larson, L. M., & Borgen, F. H. (2003). The relation of self-efficacy and interests: A meta-analysis of 60 samples. Journal of Vocational Behavior, 62(2), 221­236. (found in ERIC) Satterfield, D. W., Volansky, M., Caspersen, C. J., Engelgau, M. M., Bowman, B. A., Gregg, E. W., et al. (2003). Community-based lifestyle interventions to prevent type 2 diabetes. Diabetes Care, 26(9), 2643­2652. (MEDLINE) Wisner, K. L., Gelenberg, A. J., Leonard, H., Zarin, D., & Frank, E. (1999). Pharmacologic treatment of depression during pregnancy [Review]. Journal of the American Medical Association, 282(13), 1264­1269. (MEDLINE)
General References Bero, L., & Rennie, D. (1995). The Cochrane Collaboration. Journal of the American Medical Association, 274, 1935­1938. Girden, E. R. (1996). Evaluating research articles from start to finish. Thousand Oaks, CA: Sage. Hart, C. (1999). Doing a literature review. Thousand Oaks, CA: Sage. Khan, K. S., Kunz, R., Kleijnen, J., & Antes G. (2003). Five steps to conduct- ing a systematic review. Research in Social Medicine, 96, 118­121. Piotrowski, C., & Perdue, B. (2003). Benefits of multidatabase searching: A forensic case study. Psychological Reports, 92, 881­882. Access to MEDLINE (click on "Health") and ERIC (click on "Education and Jobs") can be obtained at www.FirstGov.gov. That site also contains access to all the U.S. government publications and links to research on thousands of topics in health, medicine, biology, sociology, and so on. Notes 1. Wisner, K. L., Gelenberg, A. J., Leonard, H., Zarin, D., & Frank, E. (1999). Pharmacologic treatment of depression during pregnancy. Journal of the American Medical Association, 282, 1264­1269. 2. Lutters, M., & Vogt, N. (2003). Antibiotic duration for treating uncomplicated, symptomatic lower urinary tract infections in elderly women (Cochrane Review). In The Cochrane Library (Issue 4). Chichester, UK: John Wiley.

AR Guide

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