Table 2.
Summary of outcome measures and characteristics of the first primary outcome (N = 124)
| Characteristics | n | (%) |
|---|---|---|
| Number of primary outcome(s) | ||
| 1 | 99 | (80) |
| 2 | 16 | (13) |
| 3 | 6 | (5) |
| > 3 | 3 | (3) |
| Types of data reported for the primary outcomea | ||
| Continuous outcome | 101 | (81) |
| Categorical outcome | 17 | (14) |
| Time-to-event outcome | 4 | (3) |
| Others | 2 | (1) |
| Specific metric for the primary outcome | ||
| Value at a time-point | 74 | (60) |
| Time-to-event | 4 | (3) |
| Change from the period-baseline | 31 | (25) |
| Within individual difference between values at the end of each period | 5 | (5) |
| Within individual difference between changes from baseline | 1 | (1) |
| Others | 8 | (6) |
| Method of aggregation for the primary outcome | ||
| Number—count of participants | 21 | (17) |
| Mean | 50 | (40) |
| Median | 4 | (3) |
| Least squares mean | 43 | (35) |
| Number—proportion/percent | 6 | (5) |
| Time frame for the primary outcome includes all randomized periods | ||
| Yes | 97 | (78) |
| No | 27 | (22) |
| Measured values presented by period | ||
| Yes | 4 | (3) |
| No | 120 | (97) |
| Provides statistical analysis for primary outcome | ||
| Yes | 78 | (63) |
| No | 46 | (37) |
| Statistical methods for analyzing primary outcome (n = 78) | ||
| ANCOVA | 9 | (11) |
| ANOVA | 14 | (18) |
| Cochran-Mantel-Haenszel | 2 | (3) |
| Generalized estimating equations | 2 | (3) |
| Generalized linear mixed model | 3 | (4) |
| Linear mixed effects model | 6 | (8) |
| Mixed model analysis | 20 | (26) |
| Mixed effects ANOVA crossover model | 3 | (4) |
| Non-inferiority/equivalence testb | 2 | (3) |
| Prescott’s test | 1 | (1) |
| t test | 3 | (4) |
| Two-sided signed-rank test | 1 | (1) |
| Wilcoxon (Mann-Whitney) | 5b | (6) |
| Wilcoxon signed-rank | 1 | (1) |
| Other | 6 | (7) |
aTime-to-event outcome reported as Continuous Data
bFor trials reporting a statistical method and a non-inferiority/equivalence hypothesis, the method was recorded
cTrial NCT01132118 reported two statistical analyses: “Wilcoxon (Mann-Whitney)” and “Regression, Linear” for the first primary outcome