PH 206 Public Health Nutrition Core Course (Critical Issues): Starting Your Literature Search

1. Introduction, and Introduction to Literature Searching:
   • A quick poll.
   • When you search for articles, etc., think of context, "upstream" factors, scope, etc.
2. Introduction to Indexing:
   • Why indexing may help you in your search.
   • PubMed’s Medical Subject Headings (MeSH), and more.
3. Searching PubMed and Other Databases:
   • Using a framework for your search.
   • Search tips.
   • In-class database exercise.
   • Other databases, besides PubMed.
   • Get it at UC: Accessing articles.
4. Critical Evaluation:
   • Does the research address the question you are asking?
   • Evidence, authority, bias, etc.
5. Citation Management:
   • Using a citation manager (like Zotero, EndNote, Mendeley, etc.)
   • Keeping track of what and how you searched.
6. How to Get Help.

What causes disease?
For any "disease" or condition, you could start by considering interactions among environmental and social factors:

Poor diet, resulting from food choices, "causes" nutritional deficiency or obesity in a population.

But consider:

• Is it "caused" by historical distribution of land use (redlining and racism in the US; colonialism in some other countries)?
• Or by the regulatory environment, including crop subsidies, food inspections, etc.?
• What about the role of NGOs, IGOs, aid networks?
• What about infrastructure, such as food distribution networks, transportation, etc.?
• Is the status of women/girls a factor?
• What about mental health issues?
• What is the role of commercial activity?
• What about the healthcare and health insurance system?

. . . Keep moving upstream!

Also, consider that how issues are framed is influenced by our assumptions and biases.

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

• 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 things that could reduce these disparities, differentiating 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.

What is a good Research Question? It is a question that:

• identifies a relevant issue in your field;
• pursues relatively uncharted research territories to address the problem;
• piques the interest of others.

This blog post has tips on how to write a good research question, including examples of bad, good, and great questions.

To reduce bias, it may be best to pose your question in a neutral manner. Examples:

• Neutral question: What is the impact of school-based physical activity interventions on time spent engaged in moderate to vigorous physical activity among children, in comparison to children not exposed to school-based interventions?
• Non-neutral question: Which school-based interventions are effective in increasing the amount of time children engage in moderate to vigorous physical activity?

However, a research question often reflects power and agency. Compare the following:

• Why are African American children expelled from school more than white children?
• Why do schools expel disproportionate numbers of African American children?

What is the question being addressed in the study you are reading? Compare:

• "Our intervention worked toward fixing Problem X."
• "The most effective interventions for fixing Problem X are: ..."
• "The effects of our intervention on Problem X are: ..."

When you read an article, answer (briefly) the following (source):

• What question are the authors addressing?
• What did they do to answer the question?
• What was their rationale for doing what they did to address their question?
• What were the findings?
• How were the authors think their findings mean?

Finding a systematic review that addresses the question you are interested in can be very helpful: take a look at the search strategy and databases used in the systematic review for tips on your search.

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 worksheet (docx) 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.

Worksheet: Developing an Efficient Search Strategy Using PICO (docx): A  fillable form that provides a PICO example and prompts you to document synonyms and MeSH headings.

Embase has a PICO search form to guide you.

SPIDER is a search structure used in qualitative research. SPIDER stands for:

• Sample;
• Phenomenon of Interest;
• Design;
• Evaluation;
• Research Type.

Once you have a search strategy, you can try the Polyglot Search tool, which helps to translate a PubMed search into the correct syntax for several other databases, including Embase, Scopus, Web of Science, and more.

Words matter!

• Do you want articles on labor or articles on labor? Or is it labour?
• Do you want articles on HIV (a virus) or articles on HIV diseases (such as AIDS)?
• What's the difference between diet, food, eating, etc.?
• Is lead a noun or a verb?

Indexing facilitates more precise search statements, especially for topics that are vague or ambiguous.

• Using index terms 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." Most topical article databases use a controlled vocabulary.
• But be aware of the fact that indexing schemes are shaped by the cultural milieu from which they originate.
• Index terms are sometimes called descriptors or thesaurus terms; in PubMed they are called Medical Subject Headings, or MeSH.

Off-campus access is limited to current UC Berkeley faculty, staff and students. Choose one of the following methods:

Library Proxy (aka EZproxy):
When you click on a link to an article, database, etc., from a library web page. you will be prompted to authenticate via CalNet.
If you click on an article (etc.) link found via a search engine or a non-UCB Library webpage, you should use this bookmarklet to access the licensed resource.

Virtual Private Network (VPN):
Download and install the VPN client to allow access the UC Berkeley licensed resources.
Make sure you select Library Access - Full Tunnel VPN when you log on.
VPN FAQ

Students: Problems setting up Library Proxy or VPN? Contact your librarian, or Student Technology Services: (510) 642-HELP, or sts-help@berkeley.edu.

Write about something you are passionate about!

Ten simple rules for writing a literature review.
Pautasso M. PLoS Comput Biol. 2013;9(7):e1003149. doi:10.1371/journal.pcbi.1003149

Conducting the Literature Search.
Chapter 4 of Chasan-Taber L. Writing Dissertation and Grant Proposals: Epidemiology, Preventive Medicine and Biostatistics. New York: Chapman and Hall/CRC, 2014.

A step-by-step guide to writing a research paper, from idea to full manuscript. Excellent and easy to follow blog post by Dr. Raul Pacheco-Vega.