• Formulate your research question
• Identify the important concepts
• Develop your initial search strategy
• Identify relevant databases and grey lit sources

Developing your research question is one of the most important steps in the evidence synthesis process. At this stage in the process, you and your team have identified a knowledge gap in your field and are aiming to answer a specific question:

• If X is prescribed, then Y will happen to patients?

OR assess an intervention:

• How does X affect Y?

OR synthesize the existing evidence

• What is the nature of X? ​

​​Whatever your aim, formulating a clear, well-defined research question of appropriate scope is key to a successful evidence synthesis.

The research question will be the foundation of your synthesis. From it your research team will identify 2-5 possible search concepts. Later, you will use these search concepts to build your search strategy. 

The nature of your question will help you figure out what type of evidence synthesis to write: Do you have a focused research question with narrow parameters? You may want a systematic review, especially if it fits into the PICO question format. Do you have a broad question that looks at answering larger, more complex, exploratory research questions? You may want a scoping review.

Remember that one type of review is not inherently better: they each serve different purposes. But all will benefit from planning and documenting your process.

Formulating a research question takes time and your team may go through different versions until settling on the right research question. To help formulate your research question, some research question frameworks are listed below.

A well-formulated research question will make the searching step easier and faster. The concepts you identify now will be used as you develop your search strategy.

PICO

The PICO model is probably the most commonly-used framework, especially for clinical research questions:

• Patient or Population in relation to the Problem
  • What are the characteristics of the patient or population?
  • What is the condition, disease, or situation you are interested in?
• Intervention or exposure
  • What is the intervention, test, or exposure you want to find out about in relation to the patient/population/problem?
• Comparison (not always applicable)
  • What is the alternative to the intervention (e.g. placebo, different drug, surgery)?
  • If the alternative is usual care or no intervention, skip Comparison
• Outcome
  • What are the relevant outcomes (e.g. morbidity, death, complications, quality of life)?

Example: Is gabapentin (intervention), compared to placebo (comparison), effective in decreasing pain symptoms (outcome) in middle aged male amputees suffering phantom limb pain (population)?

Sometimes the model is described as PICO(T), where the T stands for Time or for Type of Study (the study design(s) most appropriate to answer the question).

While PICO is a helpful framework for clinical research questions, it may not be the best choice for other types of research questions, especially outside the health sciences. Here are a few others:

PICo for Qualitative Studies

• P       Population/Problem
• I         Phenomenon of Interest
• Co    Context

Example: What are the experiences (phenomenon of interest) of caregivers providing home based care to patients with Alzheimer's disease(population) in Australia (context)?

​​SPICE

• S    Setting
• P   Perspective (for whom)
• I    Intervention/Exposure
• C   Comparison
• E   Evaluation

Example: What are the benefits (evaluation) of a doula (intervention) for low income mothers (perspective) in the developed world (setting) compared to no support (comparison)?

SPIDER

• S     Sample
• PI   Phenomenon of Interest
• D    Design
• E     Evaluation
• R    Study Type

Example: What are the experiences (evaluation) of women (sample) undergoing IVF treatment (phenomenon of interest) as assessed?
Design: questionnaire or survey or interview
Study Type: qualitative or mixed method

There are dozen of different types of these frameworks For a table of other common types, see this guide from the University of Maryland: https://lib.guides.umd.edu/SR/research_question. For a comprehensive but concise overview of the almost 40 different types of research question frameworks, see this review from the British Medical Journal: Rapid review of existing question formulation frameworks.¹

¹Published as supplemental material to Booth A, Noyes J, Flemming K, Moore G, Tunçalp Ö, Shakibazadeh E. Formulating questions to explore complex interventions within qualitative evidence synthesis. BMJ Glob Health. 2019;4(Suppl 1):e001107. Published 2019 Jan 25. doi:10.1136/bmjgh-2018-001107.

To formulate your research question, you identified the important concepts. These concepts will be the building blocks for your search.

For now, focus on the concepts. You will develop the terms later.

A simplified version of how this works can be written as:
(Concept_A) AND (Concept_B) AND (Concept_C) AND (Concept_D)

For each concept, you will develop search terms. These will be joined by OR:
(TermA1 OR TermA2 OR...) AND (TermB1 OR TermB2 OR...) AND (TermC1 OR TermC2 OR...) AND (TermD1 OR TermD2 OR...)

A search concept table like the one below can help you organize the concepts and terms.

Example: Concept tables for PubMed for the research question What is the effectiveness of acupuncture vs. hypnosis for smoking cessation?

Based on this concept table, your initial search strategy would be:

(“smoking cessation”[Mesh] OR “smoking/prevention and control”[Mesh] OR “smoking/therapy”[Mesh] OR “tobacco use disorder/prevention and control”[Mesh] OR “tobacco use disorder/therapy”[Mesh] OR smoking OR smoker*)
AND
(“hypnotherapy”[Mesh] OR hypnosis OR hypnotherapy)
AND
(“acupuncture therapy”[Mesh] OR acupuncture OR acupressure)

Most evidence syntheses in health sciences will include approximately three biomedical databases, but the others you include depend on your research question. Some frequently-used ones are described below.

Core biomedical databases:

• PubMed: publicly available online database of biomedical and medical journal records. It includes MEDLINE content
• CINAHL (Cumulative Index for Nursing and Allied Health Literature): health science literature related to nursing and allied health disciplines
• Web of Science: Multidisciplinary database covering journals in the sciences, social sciences, and arts and humanities

Other potentially useful databases:

• PsycInfo: Psychology literature and psychological aspects of other topics
• ERIC: Education-related literature, from pre-K through adult education
• Cochrane Library: includes Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials.

For additional databases, see GVSU's Databases A-Z list and sort by subject.

Grey Literature:

Grey Literature includes conference proceedings, dissertations, unpublished reports, and other literature that isn't always found within traditional databases. Read more about grey lit--what is it, why to use it, and ways to find it Here are some places to start. You don't need to identify grey lit sources just yet, but now is a good time to consider if grey literature is right for your review.