League tables for orthodontists

The aim of this study was to explore the complexities in constructing league tables purporting to measure orthodontic clinical outcomes. Eighteen orthodontists were invited to participate in a cost-effectiveness study. Each orthodontist was asked to provide information on 100 consecutively treated patients. The Index of Complexity, Outcome, and Need (ICON) was used to assess treatment need, complexity, and outcome prior to, and on completion of, orthodontic treatment. The 18 orthodontists were ranked based on achieving a successful orthodontic outcome (ICON score less than or equal to 30) and the uncertainty in both the success rates and rankings was also quantified using confidence intervals. Successful outcomes were achieved in 62 per cent of the sample (range 19–94 per cent); four of the 18 orthodontists failed to achieve more than a 50 per cent success rate. In developing league tables, it is imperative that factors such as case mix are identified and accounted for in producing rankings. Bayesian hierarchical modelling was used to achieve this and to quantify uncertainty in the rankings produced. When case mix was taken into account, the four with low success rates were clearly not as good as the top four performing orthodontists. League tables can be valuable for the individual orthodontist, groups of orthodontists, payment/insurance agencies, and the public to enable informed choice for orthodontic provision but must be correctly constructed so that users can have confidence in them.