Skip to main content

Table 4 The ratio of observed and estimated effect size in 113 randomized trials

From: Estimates of the mean difference in orthopaedic randomized trials: obligatory yet obscure

Ratio of observed effect size and estimated effect size in power calculation Follow-up time not applicable Follow-up under 3 months Follow-up between 3 and 6 months Follow-up between 6 and 12 months Follow-up over 12 months Total number of RCTs (%)
Median (IQR) 0.87 (0.7–1.1) 0.51 (0.2–0.8) 0.39 (0.2–0.6) 0.21 (0.2–0.5) 0.28 (0.1–0.6) 0.41 (0.2–0.8)
< 0.5 1 (8 %) 15 (48 %) 10 (63 %) 12 (80 %) 27 (71 %) 65 (58 %)
0.5-1.0 6 (46 %) 9 (29 %) 3 (19 %) 1 (7 %) 7 (18 %) 26 (23 %)
1.0-1.5 5 (38 %) 4 (13 %) 3 (19 %) 2 (13 %) 2 (5 %) 16 (14 %)
> 1.5 1 (8 %) 3 (10 %) 0 0 2 (5 %) 6 (5 %)