Inclusion and exclusion criteria
In a clinical trial, the investigators must specify inclusion and exclusion criteria for participation in the study.
Inclusion criteria are characteristics that the prospective subjects must have if they are to be included in the study, while exclusion criteria are those characteristics that disqualify prospective subjects from inclusion in the study. Inclusion and exclusion criteria may include factors such as age, sex, race, ethnicity, type and stage of disease, the subject’s previous treatment history, and the presence or absence (as in the case of the “healthy” or “control” subject) of other medical, psychosocial, or emotional conditions.
Inclusion and exclusion criteria are meant to ensure patients safety during the study, provide data (justification) of subject appropriateness for the study, to minimize withdrawal (also costs) and ensure that primary end-points of study are reached.
Poorly Justified Reasons for Exclusion:
- Any criteria unless the condition or intervention is specific to the criterion, or the criterion has a direct bearing on condition/intervention/results.
Strongly Justified Reasons for Exclusion:
- Unable to provide informed consent
- Placebo or intervention would be harmful
- Lack of equipoise (intervention harmful)
- Effect of intervention difficult to interpret
Potentially Justified Reasons for Exclusion
- Individual may not adhere
- Individual may not complete follow up
- Individuals do not have reliable information
Example of inclusion and exclusion criteria
Coronary Heart Disease
- Minimum outcomes: coronary deaths & non-fatal myocardial infarction
- Appropriate measures of Framingham variables (Age, sex, LDL, HDL, total cholesterol, diabetes, smoking status, hypertension)
- Cohort, nested case-control, cardiovascular trial follow-up study (or systematic review or meta-analysis of these study types) that measures a novel risk factor and estimates its predictive value after adjusting for Framingham variables
- No data
- Population or sub-population with known coronary disease or coronary disease equivalent (e.g., diabetes)
- Does not include minimum outcomes
- Does not measure Framingham variables appropriately
- Wrong study design/article format
- Van Spall, Harriette (21 March 2007). "Eligibility criteria of randomized controlled trials published in high-impact general medical journals: a systematic sampling review". The Journal of the American Medical Association. 297 (11): 1233–40. doi:10.1001/jama.297.11.1233. PMID 17374817.
- Helfand M, Buckley D, Fleming C, et al. (2009). Screening for Intermediate Risk Factors for Coronary Heart Disease. Rockville (MD): Agency for Healthcare Research and Quality (US).