Which statement combines the enrollment number and power calculations to justify the trial size?

Which statement combines the enrollment number and power calculations to justify the trial size?

• A. The overall budget and staffing plan
• B. The randomization algorithm and inclusion criteria
• C. The number of subjects planned to be enrolled; power calculations and clinical justification
• D. The data query plan

Answer: (C)

Key idea: deciding how many participants to enroll must be supported by both the statistical need and the real-world justification for the study size. The statement that includes the planned number of subjects to enroll, the power calculations, and the clinical justification best captures this. Power calculations show how many participants are needed to detect a meaningful treatment effect with a chosen level of confidence, given the expected variability. The clinical justification explains why that size is appropriate for the condition, population, anticipated effect, safety, and feasibility. When these three pieces come together, the trial size is scientifically and ethically grounded. Other aspects like budget and staffing, the specifics of the randomization algorithm with inclusion criteria, or a data query plan address different design or operational elements and do not directly justify the trial’s size or its statistical power.

Key idea: deciding how many participants to enroll must be supported by both the statistical need and the real-world justification for the study size. The statement that includes the planned number of subjects to enroll, the power calculations, and the clinical justification best captures this. Power calculations show how many participants are needed to detect a meaningful treatment effect with a chosen level of confidence, given the expected variability. The clinical justification explains why that size is appropriate for the condition, population, anticipated effect, safety, and feasibility. When these three pieces come together, the trial size is scientifically and ethically grounded.

Other aspects like budget and staffing, the specifics of the randomization algorithm with inclusion criteria, or a data query plan address different design or operational elements and do not directly justify the trial’s size or its statistical power.