Article type
Year
Abstract
Introduction/Objective: To assess the integrity of local sealed envelope randomisation within a multicentre trial.
Methods: An opportunistic before and after study of 654 participants in a 23-centre surgical trial. Two methods of randomly allocated participants to alternative treatments were compared: (a) a sealed envelope system administered locally, and (b) a centralised telephone system administered by the trial co-ordination centre.
Results: The median age of patients allocated to the experimental group with the sealed envelope system was significantly lower both overall (59 vs 63 years, p<0.01) and in particular for 3 clinicians (57 vs 72, p<0.01; 33 vs 69, p<0.01; 47 vs 72, p=0.03). No differences in median age were found between the allocation groups for the centralised system.
Discussion: Due to inadequate allocation concealment with the sealed envelope system, the randomisation process was corrupted for patients recruited from three clinicians. Centralised randomisation ensures that treatment allocation is not only secure but is also seen to be secure. Where this proves impossible, allocation should at least be performed by an independent third party. Adoption of the CONSORT reporting guidelines on the description of allocation generation and concealment will improve judgements about the likely quality of randomised controlled trials.
Methods: An opportunistic before and after study of 654 participants in a 23-centre surgical trial. Two methods of randomly allocated participants to alternative treatments were compared: (a) a sealed envelope system administered locally, and (b) a centralised telephone system administered by the trial co-ordination centre.
Results: The median age of patients allocated to the experimental group with the sealed envelope system was significantly lower both overall (59 vs 63 years, p<0.01) and in particular for 3 clinicians (57 vs 72, p<0.01; 33 vs 69, p<0.01; 47 vs 72, p=0.03). No differences in median age were found between the allocation groups for the centralised system.
Discussion: Due to inadequate allocation concealment with the sealed envelope system, the randomisation process was corrupted for patients recruited from three clinicians. Centralised randomisation ensures that treatment allocation is not only secure but is also seen to be secure. Where this proves impossible, allocation should at least be performed by an independent third party. Adoption of the CONSORT reporting guidelines on the description of allocation generation and concealment will improve judgements about the likely quality of randomised controlled trials.