Sensitivity to scale of willingness-to-pay within the context of menorrhagia.

OBJECTIVES: Willingness-to-pay (WTP) provides a broad assessment of well-being, capturing benefits beyond health. However, the validity of the approach has been questioned and the evidence relating to the sensitivity of WTP to changes in health status is mixed. Using menorrhagia (heavy menstrual bleeding) as a case study, this exploratory study assesses the sensitivity to scale of WTP to change in health status as measured by a condition-specific measure, MMAS, which includes both health and non-health benefits. The relationship between EQ-5D and change in health status is also assessed. METHODS: Baseline EQ-5D and MMAS values were collected from women taking part in a randomized controlled trial for pharmaceutical treatment of menorrhagia. Following treatment, these measures were administered along with a WTP exercise. The relationship between the measures was assessed using Spearman's correlation analysis, and the sensitivity to scale of WTP was measured by identifying differences in WTP alongside differences in MMAS and EQ5D values. RESULTS: Our exploratory findings indicated that WTP, and not EQ-5D, was significantly positively correlated with change in MMAS, providing some evidence for convergent validity. These findings suggest that WTP is capturing the non-health benefits within the MMAS measure. Mean WTP also increased with percentage improvements in MMAS, suggesting sensitivity to scale. CONCLUSION: When compared to quality of life measured using the condition-specific MMAS measure, the convergent validity and sensitivity to scale of WTP is indicated. The findings suggest that WTP is more sensitive to change in MMAS, than with EQ-5D.

Pharmaceutical treatments to prevent recurrence of endometriosis following surgery: a model-based economic evaluation.

OBJECTIVE: Conduct an economic evaluation based on best currently available evidence comparing alternative treatments levonorgestrel-releasing intrauterine system, depot-medroxyprogesterone acetate, combined oral contraceptive pill (COCP) and 'no treatment' to prevent recurrence of endometriosis after conservative surgery in primary care, and to inform the design of a planned trial-based economic evaluation. METHODS: We developed a state transition (Markov) model with a 36-month follow-up. The model structure was informed by a pragmatic review and clinical experts. The economic evaluation adopted a UK National Health Service perspective and was based on an outcome of incremental cost per quality-adjusted life year (QALY). As available data were limited, intentionally wide distributions were assigned around model inputs, and the average costs and outcome of the probabilistic sensitivity analyses were reported. RESULTS: On average, all strategies were more expensive and generated fewer QALYs compared to no treatment. However, uncertainty attributing to the transition probabilities affected the results. Inputs relating to effectiveness, changes in treatment and the time at which the change is made were the main causes of uncertainty, illustrating areas where robust and specific data collection is required. CONCLUSIONS: There is currently no evidence to support any treatment being recommended to prevent the recurrence of endometriosis following conservative surgery. The study highlights the importance of developing decision models at the outset of a trial to identify data requirements to conduct a robust post-trial analysis.

Exploring the Use of Cost-Benefit Analysis to Compare Pharmaceutical Treatments for Menorrhagia.

BACKGROUND: The extra-welfarist theoretical framework tends to focus on health-related quality of life, whilst the welfarist framework captures a wider notion of well-being. EQ-5D and SF-6D are commonly used to value outcomes in chronic conditions with episodic symptoms, such as heavy menstrual bleeding (clinically termed menorrhagia). Because of their narrow-health focus and the condition's periodic nature these measures may be unsuitable. A viable alternative measure is willingness to pay (WTP) from the welfarist framework. OBJECTIVE: We explore the use of WTP in a preliminary cost-benefit analysis comparing pharmaceutical treatments for menorrhagia. METHODS: A cost-benefit analysis was carried out based on an outcome of WTP. The analysis is based in the UK primary care setting over a 24-month time period, with a partial societal perspective. Ninety-nine women completed a WTP exercise from the ex-ante (pre-treatment/condition) perspective. Maximum average WTP values were elicited for two pharmaceutical treatments, levonorgestrel-releasing intrauterine system (LNG-IUS) and oral treatment. Cost data were offset against WTP and the net present value derived for treatment. Qualitative information explaining the WTP values was also collected. RESULTS: Oral treatment was indicated to be the most cost-beneficial intervention costing £107 less than LNG-IUS and generating £7 more benefits. The mean incremental net present value for oral treatment compared with LNG-IUS was £113. The use of the WTP approach was acceptable as very few protests and non-responses were observed. CONCLUSION: The preliminary cost-benefit analysis results recommend oral treatment as the first-line treatment for menorrhagia. The WTP approach is a feasible alternative to the conventional EQ-5D/SF-6D approaches and offers advantages by capturing benefits beyond health, which is particularly relevant in menorrhagia.

Levonorgestrel-releasing intrauterine system vs. usual medical treatment for menorrhagia: an economic evaluation alongside a randomised controlled trial.

OBJECTIVE: To undertake an economic evaluation alongside the largest randomised controlled trial comparing Levonorgestrel-releasing intrauterine device ('LNG-IUS') and usual medical treatment for women with menorrhagia in primary care; and compare the cost-effectiveness findings using two alternative measures of quality of life. METHODS: 571 women with menorrhagia from 63 UK centres were randomised between February 2005 and July 2009. Women were randomised to having a LNG-IUS fitted, or usual medical treatment, after discussing with their general practitioner their contraceptive needs or desire to avoid hormonal treatment. The treatment was specified prior to randomisation. For the economic evaluation we developed a state transition (Markov) model with a 24 month follow-up. The model structure was informed by the trial women's pathway and clinical experts. The economic evaluation adopted a UK National Health Service perspective and was based on an outcome of incremental cost per Quality Adjusted Life Year (QALY) estimated using both EQ-5D and SF-6D. RESULTS: Using EQ-5D, LNG-IUS was the most cost-effective treatment for menorrhagia. LNG-IUS costs £100 more than usual medical treatment but generated 0.07 more QALYs. The incremental cost-effectiveness ratio for LNG-IUS compared to usual medical treatment was £1600 per additional QALY. Using SF-6D, usual medical treatment was the most cost-effective treatment. Usual medical treatment was both less costly (£100) and generated 0.002 more QALYs. CONCLUSION: Impact on quality of life is the primary indicator of treatment success in menorrhagia. However, the most cost-effective treatment differs depending on the quality of life measure used to estimate the QALY. Under UK guidelines LNG-IUS would be the recommended treatment for menorrhagia. This study demonstrates that the appropriate valuation of outcomes in menorrhagia is crucial.