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Library Session for GHE group

 presented by Michael Sholinbeck

URL for this web page: www.lib.berkeley.edu/PUBL/SPH/GHE.html


Before You Start: Your Topic, the Scope of Your Search, Where to Look

What causes disease?
How you conceptualize your topic affects how you search for relevant information. Consider first perhaps the interaction and interdependence of environmental factors (eg, pollution, disasters, outbreaks) and social factors (eg, smoking, obesity, drug use). You may also wish to consider other aspects of your topic.
  » Is exacerbation of asthma in West Oakland "caused" by air pollution and/or smoking?
    » Or, is it "caused" by inadequate regulation of transportation, energy production, and/or tobacco?
      » Or by historical racism in housing and neighborhood characteristics?
        » What about genetic factors? poverty? stress?
          » What about access to appropriate prescription drugs?
Think about the wider context of your topic. Do some preliminary exploration, both in the literature and in discussions with your teachers, advisors, and peers. What are the relevant scientific and policy circumstances?

Is your topic researchable?
You may need to broaden or narrow the focus of your topic.
This may become more apparent as you search for and find information. It may prove difficult to find research on very narrow topics, or to cope with the vast literature on an un-focused, broad topic.

How researchable do you think the following topics may be?
  1. "Effects of vehicular emissions from 1995 Toyotas on elderly women in Berkeley"
  2. "Seasonal variation in PM2.5 levels in the San Francisco Bay Area"
  3. "Air pollution in the United States"

What is the scope of your search?
Literature searching always involves balancing finding all relevant citations (which means you may also find many non-relevant citations) with finding only relevant citations (which means you may miss some relevant citations).

» The search scope influences how you focus or limit your search when using online databases, as well as when you decide you have "enough."

Which disciplines are concerned with your topic?
Which aspect(s) - legal, political, environmental, behavioral etc. - of your topic is/are of interest?

» Answering these questions will help you decide which databases to search for literature.
Although PubMed may be the best place to start for most public health topics, you may miss key literature if you do not use other resources.
Use your question as the basis for deciding where to search. More information in the Beyond PubMed ... section, below.

The importance of indexing
» Do you want articles on labor (as in work) or articles on labor (as in giving birth)? Or is it labour?
Indexing facilitates more precise search statements, especially for topics that are vague or ambiguous.
Using index terms also helps you avoid the need to think of every possible synonym or alternate spelling of your search terms.
Indexing means the citations in the database are assigned terms from a controlled vocabulary; not all databases use a controlled vocabulary, however.
Index terms are sometimes called descriptors or thesaurus terms; in PubMed they are called Medical Subject Headings, or MeSH
» More information is in the database sections below.

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PubMed Tips

Citations to over 21 million journal articles (and a very small but growing number of books/book chapters),
with links to full text via Click for info on using UC-eLinks

PubMed top tips for focusing your search:

  1. Combine terms with AND or OR
  2. Use Limits (Age group, Publication type, language, etc.)
  3. Search for your term as a word in the title or title or abstract (using Limits)
  4. Use MeSH, with subheadings
  5. Try PubMed's Clinical Queries or Topic-Specific Queries
  6. Use the Related Articles link, once you find a set of relevant citations

Information on these follows:

» PubMed Quick Guide: Basic search help.
» PubMed exercise set (PDF; Public Health Library): Use these to hone your PubMed skills.

» Combining search terms with Boolean operators (AND, OR, NOT - remember Venn diagrams?)

» Limits: Limit your search by language, age group, publication type, publication date, and more. Also use Limits search for words in the article title, abstract, or Medical Subject Heading (MeSH). Note that Limits stay in effect until you clear them.

» Use Medical Subject Headings (MeSH):

» Clinical Queries: You may especially be interested in finding systematics reviews on your topic. Also consider that etiology may be used for a "cause of disease" search, and that therapy encompasses any type of intervention.
» Topic-Specific Queries use "canned" search strategies to fetch a citation subset of PubMed. Some examples of topic-specific queries include:

» Saving citations temporarily using the Clipboard
» My NCBI: Saving search results, searches, and more: customize PubMed to meet your needs.

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Beyond PubMed: Other Resources for Finding Journal Articles and More
  Click for info on using UC-eLinks     Access paid by UCB Library

Remember those PubMed "Top Tips"? Most are applicable to many other online databases.

Subjects include all aspects of agriculture: agricultural economics, nutrition, hunger, food production, agricultural chemicals, etc.
» Agricola does not use a controlled vocabulary. Use the subject descriptor index to find terms, or focus your search by using title words.
» What's not in PubMed?
    Nutritionally induced diseases, WIC program, women in rural development ...

Environmental Sciences & Pollution Management Database
Citations in ecology, environmental quality, environmental education, environmental engineering, natural resource management, pollution, risk, toxicology, and more.
» Environmental Sciences & Pollution Management Database does use controlled vocabularies. ESPM is actually a collection of several databases, many with their own controlled vocabulary. Click Search Tools then Thesaurus to select a thesaurus to use.
» What's not in PubMed?
    Air pollution forecasting, environmental equity, wastes (by industry), ...

ERIC (Educational Resources Information Center)
Access to the educational literature, including school health and health promotion. ERIC sources include journals, books, conferences and meetings, reports, theses/dissertations, and audiovisual media. ERIC also includes materials on tests, measurement, and evaluation.
» ERIC does use a controlled vocabulary. Click Search Tools then Thesaurus to browse for terms.
» What's not in PubMed?
    Environmental education, conservation education, social biology, ... curricula and lesson plans (known as "Guides, classroom, teacher")

Global Health
Citations in environmental and occupational health, food safety and hygiene, infectious diseases, medical microbiology, nutrition, public health, toxicology, zoonoses, and more. Sources include journals, books, reports, conference proceedings, patents, theses, and electronic only publications. Significantly more international coverage than PubMed.
» Global Health does use a controlled vocabulary. Use the drop-down menu and select Descriptors then click magnifying glass gif to browse the thesaurus.
» What's not in PubMed?
    Search by (relatively narrow) geographic locations (ie, setting), or country in which work published.
» Global Health Exercise (PDF)
» Global Health Help (PDF)

Citations on all aspects of human impact to the environment: pollution, sustainable agriculture, renewable energy, recycling, and more.
» GreenFILE does not use a controlled vocabulary. You can browse for Subject Terms by clicking Subject Terms at the top of the window.
» What's not in PubMed?
    Air pollution -- Mathematical models, pollution -- measurement, ...

Sociological Abstracts
Citations in demography, education, law, social psychology, and sociology. Sources include journals, books, conferences and meetings, and dissertations.
» Sociological Abstracts does use a controlled vocabulary. Click Search Tools then Thesaurus to browse for terms.
» What's not in PubMed?
    Cultural capital, peer relations, victimization, family structure, strategies, neighborhoods, social constructionism, ...
» Sociological Abstracts Exercise (PDF)
» Sociological Abstracts Fact Sheet

Web of Science
Large, multidisciplinary database; links to cited articles and times cited are provided for retrieved articles.
» Web of Science does not use a controlled vocabulary; it uses author keywords and keywords assigned algorithmically.
» What's not in PubMed?
    Scope of database is broad; best resources for cited reference searching; can sort search results by times cited.
» Search Tips for Web of Science (Flash tutorial)
» Cited Reference Searching (Flash tutorial)

    Cited Ref Diagram (from Ithaca College Library web site)

The above are but a sample of the many databases available to find article and other citations.
See the Public Health Library's Indexes and Databases web page for more.
Ask a librarian for help if you are having trouble with your topic.

Use the library catalogs to find books, reports, etc. on your topic.
Books, while not often where original research is published, can often provide an overview of a topic and get you started with some key articles.

Sources of systematic and other reviews
"Systematic reviews seek to collate all evidence that fits pre-specified eligibility criteria in order to address a specific research question. They aim to minimize bias by using explicit, systematic methods."
(from Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from www.cochrane-handbook.org).

Grey Literature/Other Resources

Grey Literature generally refers to publications not produced by commercial publishers, including reports (pre-prints, preliminary progress and advanced reports, technical reports, market research reports, etc.), theses, conference proceedings, and other documents. They are often produced by government entities, research institutions, or NGOs/IGOs.

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Critically Evaluating What You Find

What is evidence?

Reliability and validity
Adopted from Chapter 3, Conducting research literature reviews : from the Internet to paper, by Arlene Fink; Sage, 2010.
Reliable data collection: relatively free from "measurement error."
  » Is the survey written at a reading level too high for the people completing it?
  » If I measure something today, then measure it again tomorrow using the same scale, will it vary? Why?
Validity refers to how well a measure assesses what it claims to measure
  » If the survey is supposed to measure "quality of life," how is that concept defined? Is it measurable?
Extensive discussions of reliability and validity are available in several texts, such as Textbook in Psychiatric Epidemiology (3rd Ed.; M. Tsuang et al. Wiley. 2011; See chapters 5 and 7).

What to consider when looking at survey or estimated data:
Adopted from information on the UCSF Family Health Outcomes Project web site

Critical Appraisal Tools
Critical Appraisal of Intervention Studies is a free online learning module from Canada's National Collaborating Centre for Methods and Tools. It demonstrates how to assess the quality of an intervention study and to develop skill in applying the criteria for critical appraisal of an intervention study to enable you to determine whether that intervention can be applied to your own public health situation.
  » Here is a summary table of basic considerations for critical appraisal of intervention studies

The Critical Appraisal Skills Programme (UK) links to a set of brief checklist documents on critically evaluating different types of studies (eg, systematic reviews, cohort studies, RCTs, qualitative studies, etc.).

Critical appraisal of epidemiological studies and clinical trials (J. M. Elwood. Oxford University Press, 2007) has several chapters that provide detailed information on critically evaluating different kinds of studies. This book is available both online and in the Public Health Library:

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Organize Your Citations and Search Strategy

Organizing Your Literature Search/Search Results
Charts like this Literature Review Matrix (.doc) help you organize what you find in your literature search.
(This is a simplified version of the matrix presented in Health sciences literature review made easy: the matrix method, J. Garrard; Sudbury, MA: Jones and Bartlett Learning, 2011, available in the Public Health Library, call number R118.6 .G37 2011; Reference Section)
  » You can adapt RefWorks, EndNote, Zotero, or Mendeley to be used with a matrix like this by using notes or custom fields in your database.
      » Take a class to learn how to use these programs, all of which greatly simplify keeping track of citations you find.
      » This EndNote custom style was created for use with a literature review matrix; download it to the Styles folder in your EndNote program.
      » RefWorks Exercise Set / Handout (PDF; Public Health Library, 2011)

The Assignment Calculator (Univ. of Minn. Libraries) may help you organize your time when working on a research paper.

Save your search strategies: Nearly all the databases you use to find articles, etc., retain your search history. Literature reviews, like epidemiological research, should be rigorous and reproducible. Save or print your search history to help document your search strategy, which will include:

Using PubMed's Clipboard and My NCBI can help with both saving your search strategy and the citations you find;
See links in the PubMed section, above.

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What To Do When You Are Done

Congratulations! You have completed a successful, quality research project!

Please consider:

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