Table 2 Summary of outcome measures and characteristics of the first primary outcome (N = 124)
From: Registration of phase 3 crossover trials on ClinicalTrials.gov
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) |