Cost-Effectiveness Acceptability Curves and a Reluctance to Lose

Cost-effectiveness acceptability curves (CEACs) are a method used to present uncertainty surrounding incremental cost-effectiveness ratios (ICERs). Construction of the curves relies on the assumption that the willingness to pay (WTP) for health gain is identical to the willingness to accept (WTA) health loss. The objective of this paper is to explore the impact that differences between WTP and WTA health changes have on CEACs. Previous empirical evidence has shown that the relationship between WTP and WTA is not 1___1. The discrepancy between WTP and WTA for health changes can be expressed as a ratio: the accept/reject ratio (which can vary between 1 and infinity). Depending on this ratio, the area within the southwest quadrant of the cost-effectiveness plane in which any bootstrap cost-effect pairs will be considered to be cost effective will be smaller, resulting in a lower CEAC. We used data from two clinical trials to illustrate that relaxing the 1___1 WTP/WTA assumption has an impact on the CEACs. Given the difficulty in assessing the accept/reject ratio for every evaluation, we suggest presenting a series of CEACs for a range of values for the accept/reject ratio, including 1 and infinite. Although it is not possible to explain this phenomenon within the extra-welfarist framework, it has been shown empirically that individuals give a higher valuation to the removal of effective therapies than to the introduction of new therapies that are more costly and effective. In cost-effectiveness analyses where uncertainty of the ICER covers the southwest quadrant of the cost-effectiveness plane, the discrepancy between societies' WTP and WTA should be indicated by drawing multiple CEACs.Cost-effectiveness, Willingness-to-pay

The Impact of Differences in EQ-5D and SF-6D Utility Scores on the Acceptability of Cost-Utility Ratios: Results across Five Trial-Based Cost-Utility Studies

ABSTRACTObjectiveThis article investigates whether differences in utility scores based on the EQ-5D and the SF-6D have impact on the incremental cost–utility ratios in five distinct patient groups.MethodsWe used five empirical data sets of trial-based cost–utility studies that included patients with different disease conditions and severity (musculoskeletal disease, cardiovascular pulmonary disease, and psychological disorders) to calculate differences in quality-adjusted life-years (QALYs) based on EQ-5D and SF-6D utility scores. We compared incremental QALYs, incremental cost–utility ratios, and the probability that the incremental cost–utility ratio was acceptable within and across the data sets.ResultsWe observed small differences in incremental QALYs, but large differences in the incremental cost–utility ratios and in the probability that these ratios were acceptable at a given threshold, in the majority of the presented cost–utility analyses. More specifically, in the patient groups with relatively mild health conditions the probability of acceptance of the incremental cost–utility ratio was considerably larger when using the EQ-5D to estimate utility. While in the patient groups with worse health conditions the probability of acceptance of the incremental cost–utility ratio was considerably larger when using the SF-6D to estimate utility.ConclusionsMuch of the appeal in using QALYs as measure of effectiveness in economic evaluations is in the comparability across conditions and interventions. The incomparability of the results of cost–utility analyses using different instruments to estimate a single index value for health severely undermines this aspect and reduces the credibility of the use of incremental cost–utility ratios for decision-making

Cost Effectiveness of an Adherence-Improving Programme in Hypertensive Patients

Background: Non-adherence to antihypertensive drugs is high, and the economic consequences of non-adherence may be substantial. The Medication Events Monitoring System (MEMS), which is a method to improve adherence, has been shown to be a useful tool for the management of adherence problems. Objective: To assess the cost effectiveness of the MEMS compared with usual care in a population of hypertensive patients with poor adherence. The MEMS programme consisted of provision of containers fitted with electronic caps together with adherence training if indicated. Methods: In a randomised controlled trial, 164 hypertensive patients in the experimental strategy and 89 patients in the usual care strategy were followed for 5 months. Patients who had a systolic blood pressure (SBP) >=160mm Hg and/or diastolic BP (DBP) >=95mm Hg despite the use of antihypertensive drugs were eligible. Patients were recruited by a GP, and treatment took place in general practice. In the experimental strategy, electronic monitoring of the intake of antihypertensive drugs was introduced without change of medication. Unsatisfactory adherence was defined asAntihypertensives, Cost-effectiveness, Cost-utility, Hypertension, Patient-compliance