Clinical studies have specific requirements, called eligibility criteria. These criteria outline who can participate in the study. Inclusion criteria are the requirements that allow someone to participate in a clinical study. Exclusion criteria are the factors that disqualify an individual from participating. Inclusion criteria for a trial might include factors such as:
- Stage of disease
- Genetic profile
- Family history
Exclusion criteria might include factors such as specific health conditions or medications that could interfere with the treatment being tested. The website clinicaltrials.gov explains inclusion and exclusion criteria for each study in the “Eligibility Criteria” section.
Inclusion and exclusion criteria for clinical trials must be strictly followed. In some cases, these criteria may seem arbitrary, especially if a person is excluded because of one factor and otherwise is eager to participate in the trial.
However, it is important to understand that the criteria are not arbitrary. It is critical to strictly follow the protocol, for at least two reasons. The first is for the safety of participants. Many of the criteria are designed to avoid potential adverse effects of the treatment being tested by excluding individuals who may be at high risk of complications.
Another reason is to preserve the integrity of the trial. If individuals are included in a trial who don’t precisely fit the criteria stated in the protocol, there is a risk that the trial will fail to adequately test the effectiveness of the treatment. In the long run, this hurts everyone with the rare disease because it could prevent researchers from determining whether the treatment works or not.