Table 4 Problems encountered when setting up randomisation schemes
From: Use of randomisation in clinical trials: a survey of UK practice
| Â | 2003 | 2011 | Total |
|---|---|---|---|
(n = 103) | (n = 15) | (n = 118) | |
Identification of/limiting prognostic factors/strata | 11 (11%) | 4 (27%) | 15 (13%) |
No problems | 10 (10%) | 2 (13%) | 12 (10%) |
Maintaining blindness/allocation concealment | 10 (10%) | 0 (0%) | 10 (8%) |
Costs of/problems with commercial services/telephone randomisation | 6 (6%) | 0 (0%) | 6 (5%) |
Ignorance or human mistakes | 5 (5%) | 1 (7%) | 6 (5%) |
Testing and monitoring | 5 (5%) | 1 (7%) | 6 (5%) |
Problems with/unavailable computer programs | 5 (5%) | 0 (0%) | 5 (4%) |
Patients randomised out of order/misallocation | 5 (5%) | 0 (0%) | 5 (4%) |
Drug supplies/stock management | 3 (3%) | 1 (7%) | 4 (3%) |