PICO is a structured methodology utilized to formulate clear clinical questions and identify relevant studies that can answer a chosen research question.
It is a foundational tool used during the design of a systematic review or meta-analysis to develop strict inclusion and exclusion criteria.
By defining these specific parameters beforehand, researchers ensure that the literature search is highly focused and that the retrieved evidence directly addresses the clinical scenario.

The acronym dictates the specific variables that a researcher must define when constructing a study design or literature search.

Component	Description
P - Population	The specific group of subjects, patients, or demographic being studied.
I - Intervention	The active treatment, procedure, or exposure being investigated.
C - Comparator	The alternative treatment, standard of care, or placebo against which the primary intervention is compared.
O - Outcomes	The clinical endpoints, measurements, or events analyzed to assess the effect of the intervention.
± T - Timeframe	The specific duration of follow-up or the time period over which the clinical outcomes are evaluated.
± Study Design	An additional parameter frequently appended to the PICO criteria to explicitly specify the types of acceptable research methodologies (e.g., restricting the search exclusively to randomized controlled trials or observational cohort studies).