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%) |