Only 75% of majority consensus scores were in agreement between assessments, and based on Bayesian multinomial modelling we estimate that unanimous consensus scores can have repeatabilities as low as 83%.

Consensus scores did show reduced variation between assessments compared to individuals, but consensus repeatability was far from perfect. In line with other studies, intra-observer and inter-observer repeatability was moderate (63–71%), and related to the reference assessment and time taken to reach a decision. Here we use repeated assessments by three radiologists of 196 hip radiographs from 98 cats within a health-screening programme to examine intra-observer, inter-observer, majority-consensus and unanimous-consensus repeatability scores for feline hip dysplasia. While consensus approaches are generally assumed to improve diagnostic repeatability, the extent to which consensus scores are themselves repeatable has rarely been examined. One common solution is to create a ‘ consensus’ score based on a majority or unanimous decision from multiple observers. Variation in the diagnostic interpretation of radiographs is a well-recognised problem in human and veterinary medicine.

Hip dysplasia normal hip xray