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Conducting a literature search

Step by step guide to developing an expert search strategy and conducting a literature review

Objectives

Formulate your research question and determine what kind of study you would like to do.

Question Formats

A well-formulated and focused question is essential to the conduct of the review. The research question binds the scope of the project and informs the sources to search, the search syntax, the eligibility criteria.

Here is a list of commonly used frameworks to help you articulate a clearly defined research question: 

Category of Question Question Format Example
Effectiveness

Patient/Population, Intervention, Comparator, Outcome (PICO)

What is the most effective blood sugar range to guide treatment for women who develop gestational diabetes mellitus in their pregnancy?
Etiology/Risk Factors

Population, Exposure, Outcome (PEO)

 

Among newborns, what is the effect of the highest dB exposure compared to the lowest dB exposure (e.g. identified tertiles, quartiles, or quintiles) during pregnancy on postnatal hearing impairment?
Diagnostic Test Accuracy

Population, Index Test, Reference Test, Diagnosis of Interest (PIRD)
 

What is the diagnostic accuracy of duplex ultrasound compared to the reference standard for detecting symptomatic carotid stenosis?
Phenomena

Setting, Perspective, Intervention/exposure/interest, Comparison, and Evaluation (SPICE
 

In assisted living facilities, do therapy dog visits as opposed to no therapy dog visits, reduce feelings of loneliness in older residents?
Experiential

Population, Phenomena of Interest, Context (PIC)

Population, Exposure, Outcome or Themes (PEO/T)
 

What factors influence whether healthcare workers follow infection prevention and control guidelines for respiratory infectious diseases?
Scoping

Population, Concept, Context

(PCC)

What types of neurological reactions to the Human Papilloma
Virus (HPV) vaccination have been reported in people who
have received the HPV vaccine?

What is PICO?

Ask PICOA clinical question needs to be directly relevant to the patient or problem at hand and phrased in such a way as to facilitate the search for an answer. PICO makes this process easier. It is a mnemonic for the important parts of a well-built clinical question. It also helps formulate the search strategy by identifying the key concepts that need to be in the article that can answer the question.

Example

PICO examples

Source: JAMA Evidence

PICO and Question Type

question types