Table 3 Promising and discouraging population rates and decision rules for declaring study feasible

% of women who consent (i.e., screen no more than 200 eligible participants to enroll 100 patients)

55%

40%

 ≥ 50% (n ≥ 100)

Probability of declaring enrollment feasible

93%

 < 1%

% of intervention arm participants (e.g., ≥ 25/50) who complete study

55%

40%

 ≥ 50% (n ≥ 25)

Probability of declaring completion feasible

80%

9.8%