PH 293: DrPH 1st Year Seminar Library Resources: Starting DrPH Library Research

Many DrPH Competencies (PDF) are include skills that the library can help you with:

"The ability to ... explore, describe, and analyze public health problems at an advanced level; synthesize and apply evidence-based research ... and critically review relevant literature."

"The ability to ... use critical evaluation, applied research methodology, and statistical methods effectively."

"The ability to articulate the breadth and depth of social, economic, and health inequities..."

All of the above require you to be able to:
» effectively and efficiently search the scientific literature;
» determine how a particular study fits in the body of knowledge on a topic and discover trends;
» evaluate the quality of any particular study; and
» know how to find statistical and other information that supports or refutes the conclusions of a study.

What causes disease? 

How you conceptualize your topic affects how you search for relevant information.

Consider first perhaps the interaction of environmental factors (eg, pollution, outbreaks) and social factors (eg, smoking, drug use). You may also wish to consider other aspects of your topic. 

Example:

• 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?

Always keep in mind the question you are trying to answer

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, as well as the purpose and audience of your literature search, influences how you focus your search when using online databases, as well as when you decide you have "enough."

Remember that research is not a linear process; you may find yourself modifying your search terms as you explore your topic.

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. 

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 (which is a finite list of terms); 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
• Keep in mind, however that indexing schemes were created within a specific cultural milieu, and that affects their "view" of the world

Considering the question a research article addresses may help you determine if it's relevant to your needs.
Below are some examples of questions or lines of inquiry:

• Are their racial or ethnic disparities in type 1 diabetes mellitus prevalence?
• Compare and contrast personal versus "upstream" factors relevant to these disparities.
• Describe examples of what may reduce these disparities, and differentiate between personal and upstream factors. 
• If a policy or program increases disparities, what are possible reasons for this? Differentiate between personal and systemic factors.
• Describe a plan/program/policy to reduce these disparities.
• Justify why systemic or upstream factors contribute more to these disparities than personal factors.

Compare these two questions, to help evaluate any intervention studies you read:

• "Our intervention worked toward fixing Problem X"
• "The best interventions for fixing Problem X are ..."

Finding a systematic review that addresses the question you are interested in can be very helpful

What is evidence?
All research is (potentially) "evidence" and there are no "perfect" studies. 
Critically evaluating what you read will help any unearth biases or methodological shortcomings that may be present.

Is there an agenda (bias)?
It's doubtful that any study of humans is without some kind of bias, either in the study design, or in the author's pre-existing beliefs. How bias in methodology was controlled and the significance of bias in any particular study is what's relevant. 

Things to consider:

• The question being addressed: What kind of research gets funded?
• Publication bias: Research that shows no effect tends not to get published
• Conflict of interest, author affiliation, source(s) of funding: Does the researcher (or the funder) have a vested interest in the outcome?
• Documentation and assumptions: Are all stated "facts" referenced?
• Peer review: Is the article peer-reviewed? Does it matter?
• Authority: Does the researcher have the knowledge to work in this area?
• Significance of a single study: Science is an incremental process; one study rarely "changes everything"

Who pays for science? Does it matter?  (There is evidence that it does matter)
Research may be funded by:

• Government
• Industry/trade groups
• Private foundations/associations
• etc.

This article (PDF) discusses the "manufactured uncertainty" created by industry groups that sponsor research and publishing on chemicals.

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.

» Take a look at a few citations (.doc) on these topics

Reliability and validity
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? 
(Adopted from Chapter 3, Conducting research literature reviews : from the Internet to paper, by Arlene Fink; Sage, 2010.)
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:

• 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 respondents 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?

It may be useful to have a structure to help guide you when searching. 

When you formulate a research question, consider these elements:

• Phenomenon: What happened?
• Subject or Population: Who did it?
• Time: When did it happen?
• Location: Where did it happen?
• Cause or Motivation: Why did it happen?
• Process: How did it happen?

Note: It is possible that not all of the above elements will be appropriate for your search topic.
This exercise (PDF) will take you through the process of formulating a search

PICO is another popular way to structure a search.
PICO stands for Patient or Population; Intervention; Comparison or Control; Outcome.
Embase has a PICO Search option.

What else does a DrPH student need in the world of information resources?

 What about information on program development & evaluation?
    »The Community Toolbox
    »2010 User-Friendly Handbook for Project Evaluation (National Science Foundation)

 What about information on best practices?
    »Model Practices Database (NACCHO)
    »What Works for Health? (County Health Rankings, RWJF)

 What about statistical information?
    »Statistical/Data Resources (UCB Library)
    »D-Lab (UCB): D-Lab provides cross-disciplinary resources for in-depth consulting, training, software support, and more.

 What about help with academic writing?
    »Graduate Writing Center (UCB Grad Division): help on grant proposals, dissertation writing, and more