Population, Intervention, Comparison, Outcome (PICO) is a framework used to develop focused clinical research questions and guide searches for relevant evidence. It identifies the population being studied, the intervention being evaluated, the comparison or alternative, and the outcomes being measured.
In clinical research, PICO helps investigators clarify study objectives and align research questions with study design. It also supports evidence-based practice and systematic reviews by providing a consistent structure for identifying and evaluating relevant studies.