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.

OBJECTIVE: This 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. METHODS: We 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. RESULTS: We 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. CONCLUSIONS: Much 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.

Self-measurement of blood pressure at home reduces the need for antihypertensive drugs: a randomized, controlled trial.

It is still uncertain whether one can safely base treatment decisions on self-measurement of blood pressure. In the present study, we investigated whether antihypertensive treatment based on self-measurement of blood pressure leads to the use of less medication without the loss of blood pressure control. We randomly assigned 430 hypertensive patients to receive treatment either on the basis of self-measured pressures (n=216) or office pressures (OPs; n=214). During 1-year follow-up, blood pressure was measured by office measurement (10 visits), ambulatory monitoring (start and end), and self-measurement (8 times, self-pressure group only). In addition, drug use, associated costs, and degree of target organ damage (echocardiography and microalbuminuria) were assessed. The self-pressure group used less medication than the OP group (1.47 versus 2.48 drug steps; P<0.001) with lower costs ($3222 versus $4420 per 100 patients per month; P<0.001) but without significant differences in systolic and diastolic OP values (1.6/1.0 mm Hg; P=0.25/0.20), in changes in left ventricular mass index (-6.5 g/m(2) versus -5.6 g/m(2); P=0.72), or in median urinary microalbumin concentration (-1.7 versus -1.5 mg per 24 hours; P=0.87). Nevertheless, 24-hour ambulatory blood pressure values at the end of the trial were higher in the self-pressure than in the OP group: 125.9 versus 123.8 mm Hg (P<0.05) for systolic and 77.2 versus 76.1 mm Hg (P<0.05) for diastolic blood pressure. These data show that self-measurement leads to less medication use than office blood pressure measurement without leading to significant differences in OP values or target organ damage. Ambulatory values, however, remain slightly elevated for the self-pressure group.

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) > or = 160 mm Hg and/or diastolic BP (DBP) > or = 95 mm 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 as < 85% of days with the number of doses taken as prescribed. In the usual care strategy, antihypertensive treatment was intensified by the addition or change of antihypertensive drugs, if necessary, without provision of an electronic monitor. Outcome parameters included the proportion of patients with normalised blood pressure (NBP) at 5 months and QALYs. Costs were quantified from the healthcare and societal perspective. Non-parametric bootstrap simulations were performed to quantify the uncertainty around the mean estimates and cost-effectiveness acceptability curves were presented. In addition, a number of univariate sensitivity analyses were performed on deterministic variables. RESULTS: At 5 months, 3.1% (95% UI [uncertainty interval] -9.7%, +15.8%) more patients had NBP, and 0.003 (95% UI -0.005, +0.010) more QALYs were generated in the experimental strategy. A statistically significant lower percentage of patients had a dose escalation in the experimental strategy. Irrespective of the ceiling ratio for cost effectiveness, the cost-effectiveness probability was between 75% and 80% for the analysis from the healthcare perspective using proportion of patients with NBP as the outcome parameter. For the analysis from the societal perspective using QALYs as the outcome parameter, this probability was between 45% and 51%. CONCLUSION: For a time horizon of 5 months, a difference in both cost and effect could not be detected between an adherence-improving programme compared with usual care for hypertensive patients. The probability that the adherence-improving programme is cost effective is at best moderate. Moreover, the cost-effectiveness result is surrounded with considerable uncertainty and large-scale implementation warrants additional research into the economic consequences of this intervention. Patients may benefit from the use of a MEMS monitor in situations where BP targets are not reached because of suspected non-adherence and both patient and GP are reluctant to increase the dose or number of antihypertensive drugs.

Economic evaluation of duloxetine for the treatment of women with stress urinary incontinence: a Markov model comparing pharmacotherapy with pelvic floor muscle training.

BACKGROUND: Duloxetine is a serotonin and norepinephrine reuptake inhibitor and may be useful for treating women with stress urinary incontinence (SUI) in general practice. OBJECTIVE: The objective of this study was to examine the cost-effectiveness of 2 duloxetine strategies (duloxetine alone and duloxetine after inadequate response to pelvic floor muscle training [PFMT]) compared with PFMT or no treatment for women aged>or=50 years with SUI. METHODS: A Markov model with a 3-month cycle length was developed, with a time horizon of 5 years. Incontinence severity was based on incontinence episode frequency per week (IEF/week). Four SUI health states were distinguished in the model: no SUI (0 incontinence episode [IE] per week), mild SUI (19 IEs/week), moderate SUI (10-25 IEs/week), and severe SUI (>or=26 IEs/week). Transition probabilities were calculated, based on published evidence, expert opinion, and demographic data. Outcomes were expected total societal costs and expected IEs. The analysis was performed from the societal perspective of The Netherlands, and all costs were reported in year-2002 euros. One-way sensitivity and probabilistic sensitivity analyses were performed. RESULTS: In the model, providing PFMT cost euro0.03/IE avoided, compared with no treatment. Duloxetine after inadequate PFMT cost euro3.81/IE avoided, compared with PFMT One-way sensitivity analyses indicated that these results were robust regarding variation in age, IEF/week, and discount rate. Below the ceiling ratio of euro3.65/IE avoided, PFMT had the highest probability of being cost-effective. With higher ceiling ratios, duloxetine after inadequate PFMT had the highest cost-effectiveness probability. CONCLUSIONS: Treating patients with duloxetine after inadequate PFMT response yielded additional health effects in the model, but would require society in The Netherlands to pay euro3.81/IE avoided for women aged>or=50 years with SUI being treated in general practice. It is up to policy-makers to determine whether this ratio would be acceptable.

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.

Joint recovery programme versus usual care: an economic evaluation of a clinical pathway for joint replacement surgery.

OBJECTIVE: The objective of the present study was to determine the incremental cost-effectiveness of a clinical pathway for patients undergoing joint replacement, the Joint Recovery Programme (JRP), as compared with usual care. The existing care process was revised to contain costs and shorten waiting lists by facilitating patient flows and improve healthcare efficiency. METHODS: The study design was a before-after trial. In total, 160 patients undergoing total hip and total knee replacement, aged 28 to 87 years (mean age, 64.4 years), were treated either according to the Joint Recovery Programme (a standardized care process with patient education and rehabilitation in groups) or usual care. Both groups were followed for 1 year. Costs were studied from a societal perspective. Outcomes included functional level (Harris Hip score and American Knee Society score) and generic quality of life (EuroQol). RESULTS: The results indicate that the Joint Recovery Programme resulted in a significant cost saving when compared with usual care mainly as a result of a considerable (>50%) reduction in length of hospital stay. The average cost saving per patient amounted to $1261 in the total hip replacement group and $3336 in the total knee replacement group. At the same time, both functional level and quality of life were higher in the JRP group. CONCLUSIONS: Clinical pathway dominates usual care and is a highly cost-effective approach to contain costs related to joint replacement surgery without adverse consequences for patients.

Development of a questionnaire to measure hearing-related health state preferences framed in an overall health perspective.

OBJECTIVES: The objective was to develop the Audiological Disabilities Preference Index (ADPI), a measure to determine health state preferences associated with audiological disabilities. The ADPI consists of a hearing-related health state description, hearing-related health state valuation, and transformation of the latter to the overall health scale. Research questions were: a) to determine the feasibility of ADPI in an older hearing-impaired population; b) to assess gain in health state preference after hearing aid fitting; c) to evaluate the reliability of ADPI using hypothetical health states; and d) to compare the results of ADPI with the EuroQol. METHODS: The ADPI, the marker states, and the EuroQol were administered to 78 first-time hearing aid users before and 12 and 25 weeks after hearing aid fitting. RESULTS: The ADPI was feasible in an older hearing-impaired population (mean age, 69.1 years). After hearing aid fitting, all dimensions of audiological disability improved (p < .001). Change in hearing-specific health state and the latter framed in overall health were 0.27 and 0.12, respectively (p < .001). The mean values of the marker states were stable, but the intraclass correlation coefficients were low. Correlations between ADPI and hearing loss and the EuroQol, respectively, were low, while moderate with hearing aid satisfaction. There was a slight change on the EuroQol visual analog scale, with only an improvement in the feeling dimension (p < .05). CONCLUSIONS: The ADPI provides a practical and useful method to assess hearing-related health state preferences needed for clinical decision making and cost-effectiveness analysis.