Participant selection should be representative of which groups?

• A. Only the easiest to recruit.
• B. Population groups intended to benefit from the investigational product.
• C. Only past patients.
• D. All patients regardless of disease.

Answer: (B)

Trials should include participants who reflect the groups that would actually use the product, so the study results apply to those who are intended to benefit. This means enrolling a range of participants that represent the real-world population with the condition, including variations in age, sex, ethnicity, disease severity, and common coexisting conditions. When the study population mirrors the target patient group, the evidence on safety and efficacy is more generalizable and informative for clinical practice, and it helps reveal whether different subgroups may respond differently.

Choosing only the easiest to recruit would bias the sample and limit how well the results apply to the broader population. Restricting to past patients might not capture current disease dynamics or the characteristics of new patients. Including people without the disease or without the intended indication would dilute the findings and raise ethical and scientific concerns about the trial’s purpose.