Library Session for PH219D, Fall 2011

URL for this web page: www.lib.berkeley.edu/PUBL/SPH/PH291D.html

Contents:

• The Public Health Library, Location, Reference, Off-Campus Access to Library Resources
• Before You Start: Your Topic, the Scope of Your Search, Where to Look
• PubMed Tips
• Beyond PubMed: Other Resources for Finding Journal Articles and More
• Critically Evaluating What You Find
• Organize Your Citations and Search Strategy

The Public Health Library, Location, Reference, Off-Campus Access to Library Resources

Sheldon Margen Public Health Library: Library hours: M-Th 9-8, F 9-5, Sa-Su 1-5

Reference Services
In-person come to 1 University Hall (in the basement): Reference Desk hours: M-F 10-12, 2-4
Other options include IM chat (24/7) and email reference.

How to set up off-campus access to library resources (databases, online journals, etc.)

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

What causes disease?
My thought process first led me to thinking about the interaction and interdependence of environmental factors (pollution, disasters, outbreaks) and social factors (smoking, obesity, drug use).
Then I moved on to thinking a little more broadly:
  » 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?
          » What about access to appropriate prescription drugs?

Is your topic researchable?

1. "The harmful effects of domestic beer consumption among students at Cal's Big Game"
2. "Health effects of binge drinking among college students in the United States"
3. "Alcohol consumption by young adults"

  » It may prove difficult to find research on very narrow topics, or to cope with the vast literature on an un-focused, broad topic.

What is the scope of your search?

• Are you doing a comprehensive search, attempting to survey the entire literature on a topic?
• Are you doing a focused search, attempting to find key articles on your topic?
• Something in between, so you can ascertain the state of knowledge on a topic?
• Maybe you just want to find some review articles or books on your topic.

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

Which disciplines are concerned with your topic?
» Answering this question 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.

Let's talk about indexing!
» Do you want articles on labor or articles on labor? Or is it labour?
Indexing provides a way to create more precise searches for topics that are vague or ambiguous. Using index terms (sometimes called descriptors; in PubMed they are called Medical Subject Headings, or MeSH) also helps you avoid the need to think of every possible synonym or alternate spelling of your search terms. More on this in the database sections below.

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PubMed Tips

PubMed: Citations to over 21 million journal articles (and a small number of books/book chapters), with links to full text via

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

» PubMed Quick Guide: Basic search help.
» PubMed exercise set (.doc; from the Public Health Library)

» 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):

• Searching by using the MeSH Database.
  Remember: think of your concept narrowly. Look at the MeSH definition. Are you interested, for example in "HIV" (a virus) or "HIV Infections" (diseases caused by HIV).
• All MeSH Categories
  MeSH is hierarchical. This link will show you the top-level categories of MeSH. Click on any category, and you will see how MeSH narrows down. For any MeSH term, clicking on the full display will show you all the available subheadings for that term. As you select terms, add them to the search builder to begin building your search.
• MeSH Qualifiers (Subheadings): Definitions
  Narrow your MeSH searches: asthma/epidemiology looks for articles only on this aspect of asthma, not on other aspects of this disease (such as diagnosis, therapy, psychology, radiology, etc.)
• Besides disease and anatomical terms, MeSH is robust in describing probability and statistical analyses, epidemiologic methods, behaviors and attitudes, and much more.
• Check out these brief MeSH tutorials on the MeSH home page.
• Using MeSH is harder with some concepts, like life course or obesogenic environment or health impact assessment. If you can not find a MeSH (or combination of MeSHs) that adequately describe your concept, search using words or phrases in the title or title/abstract. Which MeSHs are used in the relevant citations you find? Create new search startegies using those MeSHs.

» Clinical Queries: Evidence-based PubMed filters:

• Find systematic reviews (including meta-analyses, guidelines, etc.) on your topic.
• Use Clinical Study Categories, eg etiology (for a "cause of disease" search); therapy (for any type of intervention); etc.

» Topic-Specific Queries "Canned" search strategies that retrieve a citation subset of PubMed. Topic-specific queries include:

• Comparative Effectiveness Research
• Health Services Research
• Health Disparities
• Healthy People

» Saving citations temporarily using the Clipboard
» My NCBI: Save search results (citations), searches (to get automatic updates), search history (search strategies) and more: customize PubMed to meet your needs.

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Beyond PubMed: Other Resources for Finding Journal Articles and More      

Remember those PubMed "Top Tips"? Most are applicable to the databases below as well as several other databases.

BIOSIS Previews
The most comprehensive database for life science research. Coverage includes traditional areas of biology, such as botany, zoology and microbiology, as well as related fields such as biomedicine, agriculture, pharmacology and ecology. Interdisciplinary fields such as medicine, biochemistry, biophysics, bioengineering and biotechnology are also included, as well as instrumentation and methods. Includes journal article citations, books and meeting abstracts, papers and posters.
» What's not in PubMed?
    Better searching by taxonomic data, includes meeting abstracts ...
» Guide to BIOSIS previews:  html  |  pdf

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.
» What's not in PubMed?
    Search by (relatively narrow) geographic locations (ie, setting), or country in which work published.
» Global Health Help (PDF)

PsycINFO
Citations in psychology, behavior, and related disciplines; includes citations of journal articles, conference proceedings, books and book chapters, reports and dissertations.
» What's not in PubMed?
    Economic security, community attitudes, socioeconomic class attitudes, labeling, test/measurement index ...
» PsycINFO Quick Guide (PDF)

Sociological Abstracts
Citations in demography, education, law, social psychology, and sociology. Sources include journals, books, conferences and meetings, and dissertations.
» What's not in PubMed?
    Cultural capital, peer relations, victimization, family structure, strategies, neighborhoods, social constructionism, ...
» Sociological Abstracts Exercise
» Sociological Abstracts Fact Sheet

Web of Science
Large, multidisciplinary database; links to cited articles and times cited are provided for retrieved articles.
» What's not in PubMed?
    Scope of database is broad; best resources for cited reference searching.
» Search Tips for Web of Science
» Cited Reference Searching

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.

• OskiCat: Catalog of UCB
  » OskiCat Help
• Melvyl: Catalog of all UC, and beyond
  » Next-Gen Melvyl Help

Sources of systematic and other reviews include:

• The Cochrane Library (Cochrane's systematic reviews are included in PubMed)
• Effective Public Health Practice Project Systematic Reviews (Small collection of public health systematic reviews)
• Public Health + (Methodologically sound studies from top journals in a browsable, searchable database)
• Health Evidence (Methodologically-sound reviews of health promotion and public health interventions)
• Database of promoting health effectiveness reviews (Systematic and non-systematic reviews of effectiveness in health promotion and public health worldwide)
• The Campbell Collaboration Library (Systematic reviews in psychology, behavior, etc.)
• PubMed always separates review articles among the search results - see the link labeled Review on the right side of the search results page. See also Clinical Queries (above)

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Critically Evaluating What You Find

What is evidence? Things to keep in mind:

• All research is (potentially) "evidence" and there are no "perfect" studies.
  » Not all topics have been subjected to systematic reviews. You may need to use other types of studies
• Is there an agenda (bias)?
  » It's doubtful that any study of humans is totally without some kind of bias, either in the study design, or in the author's pre-existing beliefs, not to mention the source of the research funds. How bias in methodology was controlled and the significance of bias in any particular study is what's relevant.
• Is qualitative research "evidence"?
  » If your goal is to understand beliefs and meanings in the group with whom you are working, then qualitative studies can be important.

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.)

• Look at sample sizes and survey response rates - representative of your population? Enough responses to be valid?
• Who was surveyed? - representative of population being compared to? Include group you are interested in?
• Were the survey respondants from heterogeneous groups? Do the survey questions have a similar meaning to members of different groups?
• How was survey conducted? Via telephone? - Many people only have cell phones. Random selection or targeted group?
• What assumptions and methods were used for extrapolating the data?
• Look at definitions of characteristics - Does this match your own definitions?
• When was the data collected?

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 PDF checklist documents on critically evaluating different types of studies (eg, systematic reviews, cohort studies, RCTs, qualitative studies, etc.).
• Here's some literature (.doc) on peer review, publication ethics, retraction, etc.

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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.
(Modified from 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.

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 reproducable. Save or print your search history to help document your search strategy, which will include:

• the date of the search,
• search terms used (keywords, title words, MeSHs, thesaurus terms, descriptors),
• any limits (eg, language, publication dates) that you placed on your search.
• how many relevant citations you found in each database.

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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