Table 1 Rationale or reference provided for the mean difference (MD) estimate used in power calculation in 264 RCTs
From: Estimates of the mean difference in orthopaedic randomized trials: obligatory yet obscure
| Rationale or reference provided for the estimate of the mean difference in power calculation | Number of RCTs (%) |
|---|---|
| No rationale or reference | 156 (59 %) |
| Provided some rationale or reference | 108 (41 %) |
| Rationale or reference provided by PROM and non-PROM RCTs | |
| RCTs with PROM primary outcome | 69/148 (47 %) |
| RCTs with non-PROM primary outcome | 39/116 (34 %) |
| The rationale or reference provided in power calculation | |
| MCID or MDC or PASS from psychometric study for PROM | 43 (16 %) |
| Validation study of the PROM | 3 (1 %) |
| Standardized effect size | 2 (1 %) |
| Systematic review of subject | 1 (0.4 %) |
| RCTs | 11 (4 %) |
| Observational studies | 23 (9 %) |
| Pilot study or pilot data | 5 (2 %) |
| Case series | 1 (0.4 %) |
| ‘Clinical relevance’, ‘Clinical judgement’, ‘Clinical experience’ | 15 (6 %) |
| Proportional difference to the mean value of historical cohort or MCID (27–40 % decrease) | 4 (2 %) |