Inclusion And Exclusion Criteria

TL;DR

Criteria used in clinical research to define who may join a study (inclusion) and who must be excluded (exclusion).
They focus the study population, protect participant safety, and help ensure valid, interpretable results.

Definition

Inclusion criteria are the characteristics participants must meet to be eligible for a clinical research study. Exclusion criteria are the characteristics that disqualify potential participants from the study. Together, these criteria define the population to be studied, identify eligible participants, and exclude those not suitable for the study.

Explanation

Inclusion and exclusion criteria are essential components of clinical research studies. Inclusion criteria ensure the study enrolls participants relevant to the research question and able to benefit from the study interventions. Exclusion criteria remove participants who may be at risk of adverse effects from interventions or who may not provide valid data, for example to avoid confounding. These criteria help researchers define the target population and ensure study results are relevant, applicable, safe, and valid.

Examples

Cancer drug study

Inclusion example: Participants must have a diagnosis of a specific type of cancer.
Exclusion example: Participants must not be currently receiving any other cancer treatments.

Use cases

Defining the study population and eligibility for clinical research studies.
Protecting participant safety and ensuring validity of study data and results.

Notes or pitfalls

Poorly defined inclusion or exclusion criteria can lead to confounding, risk to participants, or invalid data.
Exclusion criteria are used both to protect participants from adverse effects and to avoid confounding by concurrent treatments.

Clinical research studies
Population
Confounding
Adverse effects