A BAYESIAN APPROACHTO STOCHASTICCOST-EFFECTIVENESS ANALYSISAn Illustration and Application to BloodPressure Control in Type 2 Diabetes

The aim of this paper is to discuss the use of Bayesian methods in cost-effectiveness analysis (CEA)and the common ground between Bayesian and traditional frequentist approaches. A further aim is toexplore the use of the net benefit statistic and its advantages over the incremental cost-effectivenessratio (ICER) statistic. In particular, the use of cost-effectiveness acceptability curves is examined as adevice for presenting the implications of uncertainty in a CEA to decision makers. Although it is arguedthat the interpretation of such curves as the probability that an intervention is cost-effective given thedata requires a Bayesian approach, this should generate no misgivings for the frequentist. Furthermore,cost-effectiveness acceptability curves estimated using the net benefit statistic are exactly equivalent tothose estimated from an appropriate analysis of ICERs on the cost-effectiveness plane. The principlesexamined in this paper are illustrated by application to the cost-effectiveness of blood pressure controlin the U.K. Prospective Diabetes Study (UKPDS 40). Due to a lack of good-quality prior informationon the cost and effectiveness of blood pressure control in diabetes, a Bayesian analysis assuming anuninformative prior is argued to be most appropriate. This generates exactly the same cost-effectivenessresults as a standard frequentist analysis.