PICO and other question frameworks
PICO is an acronym used to formulate research questions and guide the search for relevant evidence.
It stands for:
• Patient/Population: Describes the group of individuals or patients being studied.
• Intervention: Specifies the treatment or intervention being considered.
• Comparison: Refers to an alternative treatment or control group.
• Outcome: Identifies the expected result or outcome of the study.

Limitations of PICO
The PICO framework is most suitable for clinical and intervention-based research questions. It may not be appropriate for all types of research and an alternative question framework might be better suited.
See PICO and other question frameworks below.
Question Frameworks
PICO
PCC
SPIDER
SPICE
ECLIPSE
PEO
COPES
Booth, A., Noyes, J., Flemming, K., Moore, G., Tunçalp, Ö., & Shakibazadeh, E. (2019). Formulating questions to explore complex interventions within qualitative evidence synthesis. BMJ global health, 4(Suppl 1), e001107. Full Text PDF
Cooke, A., Smith, D., & Booth, A. (2012). Beyond PICO: the SPIDER tool for qualitative evidence synthesis. Qualitative health research, 22(10), 1435-1443. Full Text
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), 1-10. Full Text