Table 3.

Studies in the review that satisfy the different sample size recommendations

Recommendation	Frequency (%) N = 761
Kieser et al. [11] Continuous outcomes that have ≥ 10 per arm
Satisfied	580 (76%)
Not satisfied	11 (1%)
Not applicable	170 (22%)
Julious [10] Continuous outcomes that have ≥ 12 per arm
Satisfied	563 (74%)
Not satisfied	28 (4%)
Not applicable	170 (22%)
Sim and Lewis [12] Continuous outcomes that have ≥ 28 per arm
Satisfied	329 (43%)
Not satisfied	262 (35%)
Not applicable	170 (22%)
Teare et al. [13] Continuous outcomes that have ≥ 35 per arm and binary outcomes that have ≥ 60 per arm
Satisfied	251 (33%)
Not satisfied	436 (57%)
Not applicable	74 (10%)
Whitehead et al. [7] Definitive RCTs with a continuous outcome with a target effect size of:
Extra small (< 0.1) (≥ 75 per arm)	52 (7%)
Small (0.1–0.29) (≥ 25 per arm)	389 (51%)
Medium (0.3–0.69) (≥ 15 per arm)	549 (72%)
Large (≥ 0.7) (≥ 10 per arm)	580 (76%)
Not applicable	181 (24%)