Reported presence of a data monitoring committee stratified by trial characteristics
Trial characteristic | N | Data monitoring committee, N (%) | P value | |
Reported 55 (18) | Not reported 245 (82) | |||
Number of centres | ||||
Single centre | 139 | 14 (10) | 125 (90) | <0.001 |
Multicentre | 132 | 41 (31) | 91 (69) | |
Unclear | 29 | 0 (0) | 29 (100) | |
Number of nations | ||||
Single nation | 281 | 48 (17) | 233 (83) | 0.06 |
Multinational | 19 | 7 (37) | 12 (63) | |
Sample size | ||||
N randomised, median (range) | 300 | 224 (10–60480) | 91 (10–9528) | <0.001 |
Nature of the intervention | ||||
Drug | 85 | 27 (32) | 58 (68) | 0.001 |
Vaccine | 14 | 5 (36) | 9 (64) | |
Rehabilitation or psychosocial | 30 | 1 (3) | 29 (97) | |
Prevention or screening | 14 | 3 (21) | 11 (79) | |
Surgery or radiotherapy | 9 | 0 (0) | 9 (100) | |
Communication, organisational or educational | 52 | 4 (8) | 48 (92) | |
Alternative therapeutic | 14 | 4 (29) | 10 (71) | |
Device | 29 | 2 (7) | 27 (93) | |
Other* | 53 | 9 (17) | 44 (83) | |
Primary outcome type | ||||
Behavioural | 46 | 4 (9) | 42 (91) | 0.16 |
Biomarker | 55 | 12 (22) | 43 (78) | |
Pain | 14 | 3 (21) | 11 (79) | |
Physiological | 130 | 31 (24) | 99 (76) | |
Psychological | 28 | 2 (7) | 26 (93) | |
Techniques/training | 13 | 1 (8) | 12 (92) | |
Quality of life | 5 | 0 (0) | 5 (100) | |
Other | 9 | 2 (22) | 7 (78) | |
Industry or pharmaceutical funding | ||||
Yes | 50 | 16 (32) | 34 (68) | 0.009 |
No | 250 | 39 (16) | 211 (84) |
*Included therapeutic nutritional interventions (eg, supplements, infant formula and probiotics), sensorimotor interventions, physical activity interventions and financial interventions.