Heterogeneity and rationing of knee replacement.

Abstract: Many UK commissioners have introduced eligibility criteria restricting joint replacement to patients with poor pre-operative Oxford Knee Scores to cut expenditure. This seminar discusses a study that aimed to evaluate the appropriateness of this rationing and explore heterogeneity in the costs and outcomes of knee replacement. We conducted regression analyses to estimate the impact of patient characteristics on the costs and QALYs accrued with knee replacement and an estimate of the QALYs that patients could have experienced without knee replacement. Bootstrapping was used to allow for uncertainty and for correlations between the three regression models. This seminar will present the methods and results of the study, which have been which have been published at (http://bmjopen.bmj.com/content/2/1/e000332.long). I will also discuss plans for future work, the methodological implications of dealing with heterogeneity, non-randomised comparisons and correlations between regression models and the policy implications for disinvestment and treatment eligibility criteria.