Skip to main content

Table 2 Reporting of randomized controlled trials with multiple arms by trial design

From: Reporting of analyses from randomized controlled trials with multiple arms: a systematic review

  All trials, n = 298 Trial design
   Parallel group, n = 221 Parallel group with factorial, n = 37 Crossover (n = 40)
Reporting item     
Study hypothesis defined 238 (79.9) 173 (78.3) 33 (89.1) 32 (80.0)
Baseline characteristics available per group 253 (84.9) 196 (88.7) 28 (75.7) 29 (72.5)
Results on outcomes available per group 250 (83.9) 190 (85.0) 27 (73.0) 33 (82.5)
Global test comparison     
 Planned 171 (57.4) 127 (57.5) 23 (62.2) 21 (52.5)
 Reported 116 (38.9) 84 (38.0) 18 (48.7) 14 (35.0)
Pairwise test comparisons     
 Planned 180 (60.4) 144 (65.2) 11 (29.7) 25 (62.5)
 Reported 204 (68.5) 162 (73.3) 15 (40.5) 27 (67.5)
Sample-size calculation     
 Reported 210 (70.5) 159 (72.0) 30 (81.1) 21 (52.5)
 Taken into account in the multi-arm design 41/210 (19.5) 35/159 (22.0) 5/30 (16.7) 1/21 (4.8)
Adjustment method used to control type I error due to multiple-arm design a 118 (39.6) 89 (40.3) 10 (27.0) 19 (47.50)
Title identified the study as a multiple-arm trial 130 (43.6) 101 (45.7) 19 (51.4) 10 (25.0)
  1. a For sample-size calculation or for statistical analysis.