In veterinary trials reporting and communication regarding randomisation procedures is suboptimal.
To evaluate randomisation mechanisms in the veterinary literature, all trials defined as 'randomised' were extracted from five leading veterinary journals for the year 2013. Three blinded investigators evaluated (1) if the random sequence generation was actually non-random, and (2) whether method (CONSORT item 8A) and (3) type of randomisation (CONSORT item 8B) were reported. Trialists were contacted via email to establish (1) willingness to respond to questions on randomisation procedures, (2) whether reporting of randomisation improved following a suggestion to use the CONSORT 2010 guideline. Seven per cent ((95 per cent CI 2 to 12 per cent); 8/114) of the trials defined as 'randomised' explicitly used methods that are considered non-random. Almost half of the trials (49 per cent (40 to 59 per cent); 52/106) did not report any mechanism of randomisation. Only 13 trials (12.3 per cent (6 to 19 per cent); 13/106) reported both items. 39 of 114 (34.2 per cent) trialists contacted were willing to respond to further questions on randomisation mechanisms; 4 (3.5 per cent) trialists were unwilling and 71 (62.3 per cent) trialists did not respond. Email correspondence resulted in a mean clarification of 0.7 items (95 per cent CI 0.4 to 1.0) for the 15 trials for trialists that replied. Improved adherence to CONSORT guidelines and trialists communication is imperative to increase the quality of published evidence in veterinary medicine and to reduce research waste.