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Systematic Reviews: Formulate a question

An answerable research question

A systematic review starts with a clearly defined question and uses systematic and explicit methods to identify, select and critically appraise relevant research. A variety of tools are available to break the review question into sections.

Study protocol

The protocol spells out the rationale and methods for a systematic review. It acts as a guide for searches and provides details like the population of interest, study size, location, date range, outcomes etc. It's purpose is to help ensure that results aren't arbitrary.

Formulating a question

Step 1. Identify concepts. The following tools might be helpful (more notations are available here)

Clinical questions use PICO – Patient/problem, Intervention, Control, Outcome

Business, commerce, economics use CIMO – Context, Intervention, Mechanism, Outcome

Qualitative and mixed methods use SPIDER – Sample, Phenomenon of Interest, Design, Evaluation, Research type

Qualitative methods use SPICE – Setting, Perspective, Intervention, Comparison, Evaluation

Health policy and management use ECLIPSE – Expectation, Client group, Location, Impact, Professionals, SErvice

Rehabilitation use PESICO – Patient, Environment, Stakeholders, Intervention, Comparison, Outcome

Step 2. Consider synonyms, spelling variants, acronyms, truncation and proximity operators

Step 3. Are search filters for specific research methodologies required?

Step 4. Check search strategy and revise if necessary

Useful articles

Baird, R. (2018). Systematic reviews and meta-analytic techniques. Seminars in Pediatric Surgery, 27(6), 338–344.

Cooke, A., Smith, D., & Booth, A. (2012). Beyond PICO: The SPIDER tool for qualitative evidence synthesis. Qualitative Health Research, 22(10), 1435–1443.

Methley, A. M., Campbell, S., Chew-Graham, C., McNally, R., & Cheraghi-Sohi, S. (2014). PICO, PICOS and SPIDER: A comparison study of specificity and sensitivity in three search tools for qualitative systematic reviews. BMC Health Services Research, 14(1), 579.

Stern, C., Jordan, Z., & McArthur, A. (2014). Developing the review question and inclusion criteria. AJN The American Journal of Nursing, 114(4), 53–56.

Haddaway, N. R. et al. (2018). ROSES RepOrting standards for Systemactic Evidence Synthesis: Pro forma, flow-diagram and descriptive summary of the plan and conduct of environmental systematic review and systematic maps. Environmental Evidence, 7, 7. https://doi.org/10.1186/s13750-018-0121-7 

Registering a systematic review protocol

It's a good idea to register your planned systematic review at the outset. This helps avoid duplication and allows others to see your review methods. There are a number of places a review can be registered:

Open Science Framework (OSF) Registries. Register of systematic review protocols.

Prospero: International prospective register of systematic reviews. The main site where health related systematic reviews are registered.