Characteristics of included trials
| Characteristic | Not registered | Registered | Total |
| (N=23) | (N=229) | (N=252) | |
| N, % | N, % | N, % | |
| Type of award | |||
| Programme | 3 (13.0) | 18 (7.9) | 21 (8.4) |
| Project | 6 (26.1) | 138 (60.3) | 144 (57.2) |
| Feasibility | 4 (17.4) | 25 (10.9) | 29 (11.6) |
| Career development awards* | 5 (21.7) | 23 (10.0) | 28 (10.8) |
| IIOF | - | 5 (2.2) | 5 (2.0) |
| DHB Partnership Programme | - | 16 (7.0) | 16 (6.4) |
| Explorer | - | 1 (0.4) | 1 (0.4) |
| Missing | 5 (21.7) | 3 (1.3) | 8 (3.2) |
| Type of trial | |||
| 2-arm RCT | 9 (39.1) | 170 (74.6) | 179 (71.6) |
| Multiarm RCT | 5 (21.7) | 21 (9.2) | 26 (11.4) |
| Factorial RCT | - | 7 (3.1) | 7 (2.8) |
| Cluster RCT | 7 (30.4) | 18 (7.9) | 25 (10.0) |
| Cross-over RCT | 1 (4.3) | 6 (2.6) | 7 (2.4) |
| No of centres | |||
| Single centre | 15 (65.2) | 120 (52.4) | 135 (53.6) |
| Multicentre | 4 (17.4) | 96 (41.9) | 100 (39.7) |
| Missing | 4 (17.4) | 13 (5.7) | 17 (6.7) |
| Type of intervention | |||
| Drug | 2 (8.7) | 89 (38.9) | 91 (36.0) |
| Device | 2 (8.7) | 34 (14.8) | 36 (14.4) |
| Procedure/behavioural | 17 (73.9) | 101 (44.1) | 118 (46.8) |
| Food | 2 (8.7) | 2 (0.9) | 4 (1.6) |
| Other | - | 3 (1.3) | 3 (1.2) |
| Type of participant recruited | |||
| Adult | 16 (69.6) | 179 (78.2) | 194 (77.6) |
| Child† | 6 (26.1) | 44 (19.2) | 50 (20.0) |
| Adult or child | - | 6 (2.6) | 6 (2.4) |
| Missing | 1 (4.3) | - | 1 (0.4) |
| Sample size | |||
| Target sample size‡ | 96 (31–300) | 308 (104–918) | 284 (100–800) |
| Actual sample size‡ | 80 (34–276) | 251 (95–712) | 225 (89–666) |
| Trials register§ | |||
| ANZCTR | - | 192 (83.) | 192 (76.1) |
| ClinicalTrials.gov | - | 31 (13.5) | 31 (13.5) |
| ISRCTN | - | 6 (2.6) | 6 (2.4) |
*Includes both junior and senior career awards.
†Includes adolescents.
‡Median and IQR.
§Missing information.
ANZCTR, Australia New Zealand Clinical Trials Register; DHB, District Health Board; IIOF, International Investment Opportunities Fund; ISRCTN, International Standard Randomised Controlled Trial Number; RCT, randomised controlled trial.