Mapping from disease-specific measures to health-state utility values in individuals with migraine

A Dutch cost-effectiveness analysis of fremanezumab versus best supportive care in patients with chronic migraine and inadequate response to prior preventive therapy

BACKGROUND

Chronic migraine (CM) is the most severe and burdensome subtype of migraine. Fremanezumab is a monoclonal antibody that targets the calcitonin gene-related peptide pathway as a migraine preventive therapy. This study aimed to conduct a cost-effectiveness analysis of fremanezumab from a societal perspective in the Netherlands, using a Markov cohort simulation model.

METHODS

The base-case cost-effectiveness analysis adhered to the Netherlands Authority guidelines. Fremanezumab was compared with best supportive care (BSC; acute migraine treatment only) in patients with CM and an inadequate response to topiramate or valproate and onabotulinumtoxinA (Dutch patient group [DPG]). A supportive analysis was conducted in the broader group of CM patients with prior inadequate response to 2-4 different classes of migraine preventive treatments. One-way sensitivity, probabilistic sensitivity, and scenario analyses were conducted.

RESULTS

Over a lifetime horizon, fremanezumab is cost saving compared with BSC in the DPG (saving of €2514 per patient) and led to an increase of 1.45 quality-adjusted life-years (QALYs). In the broader supportive analysis, fremanezumab was cost effective compared with BSC, with an incremental cost-effectiveness ratio of €2547/QALY gained. Fremanezumab remained cost effective in all sensitivity and scenario analyses.

CONCLUSION

In comparison to BSC, fremanezumab is cost saving in the DPG and cost effective in the broader population.

An economic evaluation of eptinezumab for the preventive treatment of migraine in the UK, with consideration for natural history and work productivity

BACKGROUND

Migraine is a highly prevalent neurological disease with a substantial societal burden due to lost productivity. From a societal perspective, we assessed the cost-effectiveness of eptinezumab for the preventive treatment of migraine.

METHODS

An individual patient simulation of discrete competing events was developed to evaluate eptinezumab cost-effectiveness compared to best supportive care for adults in the United Kingdom with ≥ 4 migraine days per month and prior failure of ≥ 3 preventive migraine treatments. Individuals with sampled baseline characteristics were created to represent this population, which comprised dedicated episodic and chronic migraine subpopulations. Clinical efficacy, utility, and work productivity inputs were based on results from the DELIVER randomised controlled trial (NCT04418765). Timing of natural history events and treatment holidays-informed by the literature-were simulated to unmask any natural improvement of the disease unrelated to treatment. The primary outcomes were monthly migraine days, migraine-associated costs, quality-adjusted life years (QALYs), incremental cost-effectiveness ratio, and net monetary benefit, each evaluated over a 5-year time horizon from 2020. Secondary analyses explored a lifetime horizon and an alternative treatment stopping rule.

RESULTS

Treatment with eptinezumab resulted in an average of 0.231 QALYs gained at a saving of £4,894 over 5 years, making eptinezumab dominant over best supportive care (i.e., better health outcomes and less costly). This result was confirmed by the probabilistic analysis and all alternative assumption scenarios under the same societal perspective. Univariate testing of inputs showed net monetary benefit was most sensitive to the number of days of productivity loss, and monthly salary.

CONCLUSIONS

This economic evaluation shows that from a societal perspective, eptinezumab is a cost-effective treatment in patients with ≥ 4 migraine days per month and for whom ≥ 3 other preventive migraine treatments have failed.

TRIAL REGISTRATION

N/A.

Cost-effectiveness of rimegepant oral lyophilisate compared to best supportive care for the acute treatment of migraine in the UK

AIMS

Migraine is the most common disabling headache disorder and is characterized by recurrent throbbing head pain and symptoms of photophobia, phonophobia, nausea, and vomiting. Rimegepant 75 mg, an oral lyophilisate calcitonin gene-related peptide antagonist, is the first treatment approved for both the acute and preventative treatment of migraine, and the first acute therapy approved in over 20-years. The objective was to assess the cost-utility of rimegepant compared with best supportive care (BSC) in the UK, for the acute treatment of migraine in the adults with inadequate symptom relief after taking at least 2 triptans, or for whom triptans are contraindicated or not tolerated.

MATERIALS AND METHODS

A de novo model was developed to estimate incremental costs and quality-adjusted life years (QALYs), structured as a decision tree followed by Markov model. Patients received rimegepant or BSC for a migraine attack and were assessed for response (pain relief at 2-h). Responders and non-responders followed different pain trajectories over 48-h cycles. Non-responders discontinued treatment while responders continued treatment for subsequent attacks, with a proportion discontinuing over time. Data sources included a post-hoc pooled analysis of the phase 3 acute rimegepant trials (NCT03235479, NCT03237845, NCT03461757), and a long-term safety study (NCT03266588). The analysis was conducted from the perspective of the UK National Health Service and Personal Social Services over a 20-year time horizon.

RESULTS

Rimegepant resulted in an incremental cost-utility ratio (ICUR) of £10,309 per QALY gained vs BSC, which is cost-effectiveness at a willingness to pay threshold of £30,000/QALY. Rimegepant generated +0.44 incremental QALYs and higher incremental lifetime costs (£4,492). Improved QALYs for rimegepant were a result of less time spent with severe and moderate headache pain.

CONCLUSION

This study highlights the economic value of rimegepant which was found to be cost-effective for the acute treatment of migraine in adults unsuitable for triptans.

Evaluation of the effect of erenumab on migraine-specific questionnaire in patients with chronic and episodic migraine

Erenumab is a fully human anti-canonical calcitonin gene-related peptide receptor monoclonal antibody approved for migraine prevention. The Migraine-Specific Quality-of-Life Questionnaire (MSQ) is a 14-item patient-reported outcome instrument that measures the impact of migraine on health-related quality of life. Erenumab data from four phase II/III clinical trials were used to develop an item response theory (IRT) model within a nonlinear mixed effects framework, (i) evaluate the MSQ item information with respect to patient disability, (ii) characterize the longitudinal progression of the MSQ, and (iii) quantify the effect of erenumab on the MSQ in patients with migraine. The majority (80%) of information was found to be contained in 9 out of 14 items, extending the current knowledge on the reliability of the MSQ as a psychometric tool. Simulations across three MSQ domains show significant improvement from baseline, exceeding minimally important differences. Overall, the IRT model platform developed herein allows for systematic quantification of the effect of erenumab on the MSQ in patients with migraine.

Impact of monthly headache days on migraine-related quality of life: Results from the Chronic Migraine Epidemiology and Outcomes (CaMEO) study

OBJECTIVE

To characterize the direct impact of monthly headache days (MHDs) on health-related quality of life (HRQoL) in people with migraine and the potential mediating effects of anxiety, depression, and allodynia.

BACKGROUND

Although the general relationship between increased migraine frequency (i.e., MHDs) and reduced HRQoL is well established, the degree to which reduced HRQoL is due to a direct effect of increased MHDs or attributable to mediating factors remains uncertain.

METHODS

Cross-sectional baseline data from participants with migraine who completed the Core and Comorbidities/Endophenotypes modules in the 2012-2013 US Chronic Migraine Epidemiology and Outcomes (CaMEO) study, a longitudinal web-based survey study, were analyzed. The potential contribution of depression, anxiety, and/or allodynia to the observed effects of MHDs on HRQoL as measured by the Migraine-Specific Quality-of-Life Questionnaire version 2.1 (MSQ) was evaluated.

RESULTS

A total of 12,715 respondents were included in the analyses. The MSQ domain scores demonstrated progressive declines with increasing MHD categories (B = -1.23 to -0.60; p < 0.001). The observed HRQoL decrements associated with increasing MHDs were partially mediated by the presence of depression, anxiety, and allodynia. The MHD values predicted 24.0%-32.4% of the observed variation in the MSQ domains. Depression mediated 15.2%-24.3%, allodynia mediated 9.6%-16.1%, and anxiety mediated 2.3%-6.0% of the observed MHD effects on the MSQ.

CONCLUSIONS

Increased MHD values were associated with lower MSQ scores; the impact of MHDs on the MSQ domain scores was partially mediated by the presence of depression, anxiety, and allodynia. MHDs remain the predominant driver of the MSQ variation; moreover, most of the variation in the MSQ remains unexplained by the variables we analyzed. Future longitudinal analyses and studies may help clarify the contribution of MHDs, comorbidities, and other factors to changes in HRQoL.

Modeling Monthly Migraine-Day Distributions Using Longitudinal Regression Models and Linking Quality of Life to Inform Cost-Effectiveness Analysis: A Case Study of Fremanezumab in Japanese-Korean Migraine Patients

BACKGROUND AND OBJECTIVES

As regression approaches have been used more recently to model the effectiveness and health-related quality of life (HRQOL) of novel migraine treatments, an example is provided for fremanezumab. The objective is to estimate the distribution of mean monthly migraine days (MMD) as a continuous variable and corresponding migraine-specific utility values as a function of the MMD, to inform health states in a cost-effectiveness model (CEM).

METHODS

Three longitudinal regression models (zero-adjusted gamma [ZAGA], zero-inflated beta-binomial [ZIBB], and zero-inflated negative binomial [ZINBI]) were fitted to Japanese-Korean clinical trial data of episodic (EM) and chronic migraine (CM) patients treated with fremanezumab or placebo, to estimate MMD over a period of 12 months. The EQ-5D-5L and the migraine-specific quality-of-life (MSQ), mapped to the EQ-5D-3L, questionnaires were used to measure HRQOL. Migraine-specific utility values were estimated as a function of MMD using a linear mixed effects model.

RESULTS

The ZIBB models fitted the data best in estimating the distribution of mean MMD over time. MSQ-derived values were more sensitive than the EQ-5D-5L values for the effect of the number of MMD on HRQOL, with higher values for less MMD and more time on treatment.

CONCLUSIONS

Using longitudinal regression models to estimate MMD distributions and linking utility values as a function is an appropriate method to inform CEMs and capture inter-patient heterogeneity. The observed distribution shifts demonstrated fremanezumab's effect at reducing MMD for both EM and CM patients, while treatment effect on HRQOL was captured by MMD and time on treatment.

Estimating treatment effects on health utility scores for patients living with migraine: a post hoc analysis of the DELIVER trial

BACKGROUND

This post hoc analysis aimed to estimate eptinezumab's therapeutic effect on health utilities and determined to which extent monthly migraine days (MMDs) explain changes in health utilities.

RESEARCH DESIGN/METHODS

DELIVER, a randomized, double-blind, placebo-controlled phase 3b trial (NCT04418765), investigated eptinezumab efficacy and safety in patients with 2-4 prior migraine treatment failures. Regression analysis explored the relationship between utility scores and MMDs, with eptinezumab treatment as a covariate along with MMDs to identify any MMD-independent effect on utilities. Path analysis quantified eptinezumab's impact as mediated through MMD reduction.

RESULTS

The base case model showed that each reduction in MMD was associated with a mean utility score increase (0.0189; 95% CI: 0.0180, 0.0198; P < 0.001). Mean utility score was generally higher for eptinezumab versus placebo, justifying addition of treatment effect to the base case model. Patients administered eptinezumab had on average 0.0562 (95% CI: 0.0382, 0.0742; P < 0.001) higher utility versus placebo when controlling for number of MMDs. From path analysis, MMD reduction resulting from eptinezumab treatment accounted for 53% additional utility gain observed in patients.

CONCLUSIONS

Changes in MMDs alone inadequately captured migraine's impact on patient utility, as there was also a positive eptinezumab-driven, treatment-specific impact on utility score.

TRIAL REGISTRATION

The trial is registered at ClinicalTrials.gov (CT.gov identifier: NCT04418765).

Health State Utility Mapping of Rimegepant for the Preventive Treatment of Migraine: Double-Blind Treatment Phase and Open Label Extension (BHV3000-305)

INTRODUCTION

The objectives of this study were to (1) report long-term health-related quality of life (HRQoL) outcomes among patients using rimegepant preventatively in BHV3000-305 (NCT03732638) open-label extension (OLE) and (2) map Migraine-Specific Quality of Life questionnaire version 2.1 (MSQv2) to EQ-5D-3L utility values over the double-blind treatment (DBT; 0-12 weeks) and the OLE (13-64 weeks) to assess the influence of treatment on these values.

METHODS

This was a post hoc analysis using data from a rimegepant study for the prevention of migraine (BHV3000-305). Adult patients with migraine took either rimegepant 75 mg or placebo every other day (EOD) during the DBT phase. All patients received rimegepant during the OLE. MSQv2 was measured at baseline, weeks 12, 24, and 64. A validated algorithm was used to map MSQv2 scores to EQ-5D utilities.

RESULTS

Baseline data were available for 347 patients treated with placebo and 348 treated with rimegepant in the DBT period, who continued to the OLE. Baseline EQ-5D utilities were similar between trial arms: 0.598 for placebo and 0.614 for rimegepant. EQ-5D improved from baseline to week 12 and utilities increased by + 0.09 for placebo and + 0.10 for rimegepant (p value = 0.011). By 24 weeks, at which point patients who were originally randomized to placebo had received rimegepant 75 mg EOD for 12 weeks, HRQoL measures (MSQv2 and EQ-5D) were similar across groups, demonstrating rapid onset of treatment effect. This HRQoL improvement was durable out to 64 weeks.

CONCLUSION

Compared to placebo, treatment with rimegepant 75 mg was associated with greater improvement in EQ-5D utilities during the 12-week DBT phase. Patients originally randomized to placebo experienced a similar improvement in EQ-5D utilities after switching to rimegepant during the OLE, demonstrating that benefits are realized within 12 weeks of active treatment. This preventive effect was durable out to 64 weeks and was associated with an additional increase in HRQoL over time.

TRIAL REGISTRATION

NCT03732638.

HIT-6 and EQ-5D-5L in patients with migraine: assessment of common latent constructs and development of a mapping algorithm

OBJECTIVE

The aims of this study were to assess whether there is a conceptual overlap between the questionnaires HIT-6 and EQ-5D and to develop a mapping algorithm allowing the conversion of HIT-6 to EQ-5D utility scores for Germany.

METHODS

This study used data from an ongoing randomised controlled trial for patients suffering from migraine. We assessed the conceptual overlap between the two instruments with correlation matrices and exploratory factor analysis. Linear regression, tobit, mixture, and two-part models were used for mapping, accounting for repeated measurements, tenfold cross-validation was conducted to validate the models.

RESULTS

We included 1010 observations from 410 patients. The EQ-5D showed a substantial ceiling effect (47.3% had the highest score) but no floor effect, while the HIT-6 showed a very small ceiling effect (0.5%). The correlation between the instruments' total scores was moderate (- 0.30), and low to moderate among each domain (0.021-0.227). The exploratory factor analysis showed insufficient conceptual overlap between the instruments, as they load on different factors. Thus, there is reason to believe that the instruments' domains do not capture the same latent constructs. To facilitate future mapping, we provide coefficients and a variance-covariance matrix for the preferred model, a two-part model with the total HIT-6 score as the explanatory variable.

CONCLUSION

This study showed that the German EQ-5D and the HIT-6 lack the conceptual overlap needed for appropriate mapping. Thus, the estimated mapping algorithms should only be used as a last resort for estimating utilities to be employed in economic evaluations.

Monthly migraine days, tablet utilization, and quality of life associated with Rimegepant - post hoc results from an open label safety study (BHV3000-201)

Background

The objective of this study was to describe patterns in monthly migraine days (MMD) and tablet utilization, and to estimate health-related quality of life (HRQoL) measures in patients treated as needed (PRN) with rimegepant 75 mg over 52-weeks.

Methods

Eligible subjects were adults with ≥1 year history of migraine and ≥ 6 MMD at baseline, who used rimegepant 75 mg up to once daily PRN (at their discretion) for up to 52-weeks in an open-label safety study (BHV3000–201; NCT03266588). Mean MMD were calculated at each 4-week period, along with mean monthly tablets taken. Migraine-specific quality of life (MSQv2) data were mapped to EQ-5D utilities and used to characterize HRQoL over time. A published network meta-analysis was used to characterize pain hours as well as time periods spent migraine free.

Results

One thousand forty four subjects were included in this post-hoc analysis. Overall mean MMD were 10.9 at baseline and decreased to 8.9 by week 52. Tablet use remained stable over the follow-up period. A total of 0.08 incremental QALYs were associated with rimegepant use.

Conclusion

For subjects with 6 or more MMD, acute treatment of migraine attacks with rimegepant 75 mg on a PRN basis over one-year of follow-up was found to be associated with reduced MMD frequency without an increase in monthly tablet utilization, and improved HRQoL. There was no evidence of medication-related increases in MMDs when rimegepant 75 mg was used as needed for the acute treatment of migraine over 52-weeks.

Trial registration

ClinicalTrials.gov identifier NCT03266588.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-021-01378-5.

Mapping Migraine-Specific Quality of Life to Health State Utilities in Patients Receiving Rimegepant

INTRODUCTION

Migraine is a debilitating neurological condition, affecting up to 15% of Americans. Recent estimates from a long-term safety study of rimegepant showed evidence of decreased monthly migraine days (MMD) in people with episodic migraine treated with rimegepant 75 mg. The objective of this study was to characterize migraine-specific quality of life version 2.1 (MSQv2) scores and corresponding mapped EuroQol-5 Dimensions-3 Level (EQ-5D-3L) utility values.

METHODS

Study participants were randomized into two treatment regimens: individuals with 2-14 MMD received rimegepant 75 mg as needed (PRN), and those with 4-14 MMD at baseline who received rimegepant on a fixed every-other-day schedule plus an as needed dose on days they did not treat (QOD + PRN). MSQv2 was mapped to EQ-5D-3L utilities using a validated algorithm. Outcomes were assessed for the PRN arm at baseline weeks 12, 24, 36, and 52 and for the QOD + PRN arm at baseline and week 12.

RESULTS

At baseline, MSQv2 data were available for 1,800 patients: 1,033 with 2-8 MMD in the PRN group, 481 with 9-14 MMD in the PRN group, and 286 with 4-14 MMD in the QOD + PRN group. For all MSQv2 domains as well as mapped utility values, outcomes improved over each study visit. At baseline, EQ-5D-3L utilities were 0.66, 0.63, and 0.65 for the 2-8 MMD PRN, 9-14 MMD PRN, and 4-14 MMD QOD + PRN groups, respectively. At end-of-study, utilities had increased by + 0.09, + 0.10, and + 0.12 for the three groups, respectively (p < 0.001 for all comparisons with baseline). Similar trends in improvement were observed across MSQv2 subdomains; all differences were statistically significant.

CONCLUSIONS

Rimegepant 75 mg, which has been shown to be associated with reduced MMD, is associated with improvement in MSQv2 domains over time, leading to estimated improvement in EQ-5D-3L utilities. While this improvement was observed in all patient-groups, it was most pronounced in those with higher MMD and those taking rimegepant QOD + PRN.

TRIAL REGISTRATION

Clinical Trials NCT03266588.

The estimation of a preference-based single index for the IBS-QoL by mapping to the EQ-5D-5L in patients with irritable bowel syndrome

Purpose

The Irritable Bowel Syndrome Quality of Life (IBS-QoL) questionnaire is a commonly used and validated IBS-specific QoL instrument. However, this questionnaire is in contrast to the EQ-5D-5L, not preference-based and as such does not allow calculation of QALYs. The objective of this study was to describe the convergent- and known-group validity of both questionnaires and to develop a mapping algorithm from EQ-5D-5L which enable IBS-QoL scores to be transformed into utility scores for use in economic evaluations.

Methods

We used data from two multicenter randomized clinical trials, which represented the estimation and external validation dataset. The convergent validity was investigated by examining correlations between the EQ-5D-5L and IBS-QoL and the known-group validity by calculating effect sizes. Ordinary least squares (OLS), censored least absolute deviations (CLAD), and mixture models were used in this mapping approach.

Results

283 IBS patients were included (n = 189 vs. n = 84). Mean IBS-QoL score was 71.13 (SD 15.66) and mean EQ-5D-5L utility score was 0.73 (SD 0.19). The overall sensitivity of the IBS-QoL and EQ-5D-5L to discriminate between patient and disease characteristics was similar. CLAD model 4, containing the total IBS-QoL score and squared IBS-SSS (IBS severity scoring system), was chosen as the most appropriate model to transform IBS-QoL scores into EQ-5D-5L utility scores.

Conclusion

This study reports the development of an algorithm where the condition-specific questionnaire IBS-QoL can be used to calculate utility values for use in economic evaluations. Including a clinical measure, IBS-SSS, in the model improved the performance of the algorithm.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11136-021-02995-y.

Assessment of Utility in Migraine: Mapping the Migraine-Specific Questionnaire to the EQ-5D-5L

INTRODUCTION

There are increasing demands for studies of cost-effectiveness to allocate resources for disease prevention and treatment strategies. The aim of this study is to measure quality of life in migraineurs, based on the Migraine-Specific Questionnaire (MSQ) and EQ-5D-5L, and thereafter map an algorithm to estimate health-state utility values from the MSQ in individuals with migraine.

METHODS

In this cross-sectional study conducted between May and July 2018 in a tertiary headache clinic in Tehran, Iran, migraineurs diagnosed based on International Classification of Headache Disorders (ICHD)-3β were enrolled and were asked to complete the MSQ questionnaire and EQ-5D questionnaire. The Spearman correlation coefficient (ρ) was calculated to measure the correlation between the EQ-5D-5L and MSQ v2.1 domains' score. A P value of <.05 was considered statistically significant. After statistical analysis, several regression models were presented to map the results of the MSQ domains to the utility index, and the preferred model was achieved based on goodness of fit and the model's predictive performance.

RESULTS

The preferred MSQ algorithm had approximately the same prediction errors in all migraineurs, episodic and chronic migraine (root mean square error 0.24, 0.24, and 0.23, respectively). The preferred MSQ model explained a variance of 0.26 (R²) in episodic and 0.38 in chronic migraine in the EQ-5D-5L questionnaire.

CONCLUSION

The preferred MSQ mapping algorithm will be suitable in estimating health state utilities in trials of patients with migraine that contain MSQ scores but lack utility values.

Cost-Effectiveness of Erenumab for the Preventive Treatment of Migraine in Patients with Prior Treatment Failures in Sweden

BACKGROUND

Migraine is a common neurological disease that disproportionately affects females and has a peak incidence during productive years, resulting in significant burden.

OBJECTIVE

The aim of the study was to determine the cost effectiveness of erenumab for the preventive treatment of migraine.

METHODS

A hybrid decision-tree plus Markov model was developed to evaluate the cost effectiveness of erenumab as a migraine treatment compared with best supportive care only for patients experiencing at least 4 monthly migraine days for whom at least two prior preventive treatments had failed. Clinical efficacy data were based on results from four randomized controlled trials of erenumab against placebo. The primary outcomes were costs, migraine days, and quality-adjusted life-years (QALYs). An incremental cost-effectiveness ratio (ICER) was estimated as the cost per QALY gained. The cost per migraine day avoided was also estimated, as were disaggregated direct and indirect costs. The analysis was conducted from Swedish societal and healthcare system perspectives based on total migraine, chronic migraine and episodic migraine populations, using a discount rate of 3% applied to both costs and health benefits and using year 2019 values.

RESULTS

In the base-case deterministic analyses, erenumab treatment resulted in ICERs of Swedish krona (SEK) 34,696 (€3310) and SEK301,565 (€28,769) per QALY gained in the total migraine and episodic migraine populations, respectively. Erenumab was dominant in the chronic migraine population. In the total migraine population, the use of erenumab resulted in a net benefit to society of SEK81,739 (€7773) per patient, assuming a willingness-to-pay threshold of SEK300,000 (€28,528) per QALY.

CONCLUSIONS

Our analysis suggests that erenumab is a cost-effective treatment for migraine with a willingness-to-pay threshold of SEK300,000 per QALY.

The Health and Productivity Burden of Migraines in Australia

OBJECTIVE

This study aimed to quantify the health and productivity burden of migraines in Australia, measured by quality-adjusted life years (QALYs), productivity-adjusted life years (PALYs, a novel measure of productivity), and associated health-care and broader economic costs.

METHODS

A Markov state-transition model was constructed to simulate follow-up of Australians aged 20-64 years over the next 10 years. The model was first run using current prevalence estimates of migraine. It was then rerun assuming that people with migraine hypothetically did not have the condition. Differences in outcomes between the 2 model simulations represented the health and productivity burden attributable to migraine. All data inputs were obtained from published sources. Gross domestic product (GDP) per equivalent full-time worker in Australia was used to reflect the cost of each PALY (AU$177,092). Future costs and outcomes were discounted by 5% annually.

RESULTS

Currently, 1,274,319 million (8.5%) Australians aged 20-64 years have migraine. Over the next 10 years, migraine was predicted to lead to a loss of 2,577,783 (95% confidence interval [CI] 2,054,980 to 3,000,784) QALYs among this cohort (2.02 per person and 2.43% of total QALYs), and AU$1.67 (95% CI $1.16 to $2.37) billion in health-care costs (AU$1313 per person, 95% CI $914 to $1862). There would also be 384,740 (95% CI 299,102 to 479,803) PALYs lost (0.30 per person and 0.53% of total PALYs), resulting in AU$68.13 (95% CI $44.42 to $98.25) billion of lost GDP (AU$53,467 per person, 95% CI $34,855 to $77,102).

CONCLUSION

Migraines impose a substantial health and economic burden on Australians of working age. Funding interventions that reduce the prevalence of migraines and/or its effects are likely to provide sound return on investment.

Economic consequences of migraine in Sweden and implications for the cost-effectiveness of onabotulinumtoxinA (Botox) for chronic migraine in Sweden and Norway

BACKGROUND

Migraine is a common and incapacitating condition, with severe impact on the quality of life (QoL) of the afflicted and their families, and negative economic consequences through decreased workforce participation, reduced functional ability and elevated healthcare costs. This study aimed to describe the economic consequences of migraine in Sweden using cost of illness survey data and, based on this data, assess the cost-effectiveness of onabotulinumtoxinA (Botox) for the treatment of chronic migraine in Sweden and Norway.

METHODS

A survey study was conducted in Swedish migraine patients, with questions on patient characteristics, headache frequency and severity, effect on daily activities and work, QoL, health resource utilization, and medication use. Resulting costs were estimated as annual averages over subgroups of average monthly headache days. Some results were used to inform a Markov cost-effectiveness chronic migraine model. The model was adapted to Sweden and Norway using local data. The analysis perspective was semi-societal. Results' robustness was tested using one-way, structural, and probabilistic sensitivity analyses.

RESULTS

Results from the cost of illness analysis (n = 454) indicated a clear correlation between decreased QoL and increased costs with increasing monthly headache days. Total annual costs ranged from EUR 6221 in patients with 0-4 headache days per month, to EUR 57,832 in patients with 25-31. Indirect costs made up the majority of costs, ranging from 82% of total costs in the 0-4 headache days group, to 91% in 25-31 headache days. The cost-effectiveness analyses indicated that in Sweden, Botox was associated with 0.223 additional QALYs at an additional cost of EUR 4126 compared to placebo, resulting in an incremental cost-effectiveness ratio (ICER) of EUR 18,506. In Norway, Botox was associated with 0.216 additional QALYs at an additional cost of EUR 4301 compared to placebo, resulting in an ICER of EUR 19,954.

CONCLUSIONS

In people with migraine, an increase in monthly headache days is clearly related to lower QoL and higher costs, indicating considerable potential costs-savings in reducing the number of headache days. The main cost driver for migraine is indirect costs. Botox reduces headache days and is a cost-effective treatment for chronic migraine in Sweden and Norway.

A mapping study in mainland China: predicting EQ-5D-5L utility scores from the psoriasis disability index

Aims: This study aims to develop a mapping algorithm that can be used to predict 5-level EQ-5D (EQ-5D-5L) utility scores from the Psoriasis Disability Index (PDI) for further use in cost-utility analysis among psoriasis patients.Materials and Methods: A total of 321 participants with psoriasis was recruited in a dermatology clinic from a tertiary hospital in China. The EQ-5D-5L utility scores were scored using the Chinese-specific value set. Three model specifications were used and each one was estimated using three different statistical techniques, including the ordinary least squares (OLS), the Tobit regression and the generalized linear model (GLM). The goodness-of-fit of mapping performance was estimated by using two common indicators: the mean absolute error (MAE) and the mean square error (MSE).Results: A final validated sample of 321 psoriasis patients was analyzed in the study. The patients had a mean ± standard deviation (SD) age of 39.7 ± 12.9 years, and the EQ-5D-5L state utility score is 0.899 ± 0.106. Among all the models considered, the OLS linear model based on the four PDI item scores was selected as the best model due to higher accuracy (MAE = 0.1334 and 0.1557 for the estimation and validation sample separately).Limitations: The main limitation of this study is that the survey site was limited to one hospital and not more broadly representing the whole of China. Additionally, there are some missing data in the full sample and an absence of an external dataset to validate the algorithms.Conclusions: The mapping algorithms reported in this paper can be used to predict the EQ-5D-5L utilities from the PDI; however, similar to other mapping studies in the literature it can only serve as the second-best approach to elicit utilities from disease-specific instruments.

Updated cost-effectiveness analysis of onabotulinumtoxinA for the prevention of headache in adults with chronic migraine who have previously received three or more preventive treatments in the UK

Aims: OnabotulinumtoxinA is recommended by NICE for the treatment of chronic migraine. This economic evaluation provides updated estimates of the cost-effectiveness of onabotulinumtoxinA for chronic migraine using new utility estimates in an existing model structure.Methods: A previously published model was revised to include EQ-5D utility estimates from a large observational study (REPOSE; n = 633). Efficacy data were taken from the pooled phase III PREEMPT clinical trial program, while resource utilization estimates were obtained from the International Burden of Migraine Study (IBMS). The model estimated costs and quality-adjusted life years (QALYs) gained over 2 years from the UK NHS perspective.Results: OnabotulinumtoxinA treatment resulted in total discounted incremental costs of £1,204 and an incremental discounted QALY gain of 0.07 compared with placebo in patients with chronic migraine who have previously failed three or more preventive treatments, corresponding to an incremental cost-effectiveness ratio (ICER) of £16,306 per QALY gained. Scenario analysis showed that the administration of onabotulinumtoxinA by a specialist nurse rather than a neurology consultant reduced the ICER from £16,306 to £13,832 per QALY gained. Removal of the positive stopping rule recommended in current NICE guidance increased the ICER to £20,768 per QALY for onabotulinumtoxinA vs. placebo. Combining these two scenarios produced an ICER of £17,686 per QALY gained.Conclusion: NICE recommended onabotulinumtoxinA for the prevention of chronic migraine in 2012 amid concerns about the uncertainty of ICER estimates, with a positive stopping rule used to manage some of these uncertainties. Since the publication of the NICE guidance, the REPOSE study provides a more recent source of utility data based on real-world evidence. The results of analyses including these utilities suggest that the application of the positive stopping rule may not be necessary to ensure cost-effectiveness and that this aspect of the current NICE guidance for onabotulinumtoxinA may merit reconsideration.

Longitudinal assessment of utilities in patients with migraine: an analysis of erenumab randomized controlled trials

Background

Cost-effectiveness analyses in patients with migraine require estimates of patients’ utility values and how these relate to monthly migraine days (MMDs). This analysis examined four different modelling approaches to assess utility values as a function of MMDs.

Methods

Disease-specific patient-reported outcomes from three erenumab clinical studies (two in episodic migraine [NCT02456740 and NCT02483585] and one in chronic migraine [NCT02066415]) were mapped to the 5-dimension EuroQol questionnaire (EQ-5D) as a function of the Migraine-Specific Quality of Life Questionnaire (MSQ) and the Headache Impact Test (HIT-6™) using published algorithms. The mapped utility values were used to estimate generic, preference-based utility values suitable for use in economic models. Four models were assessed to explain utility values as a function of MMDs: a linear mixed effects model with restricted maximum likelihood (REML), a fractional response model with logit link, a fractional response model with probit link and a beta regression model.

Results

All models tested showed very similar fittings. Root mean squared errors were similar in the four models assessed (0.115, 0.114, 0.114 and 0.114, for the linear mixed effect model with REML, fractional response model with logit link, fractional response model with probit link and beta regression model respectively), when mapped from MSQ. Mean absolute errors for the four models tested were also similar when mapped from MSQ (0.085, 0.086, 0.085 and 0.085) and HIT-6 and (0.087, 0.088, 0.088 and 0.089) for the linear mixed effect model with REML, fractional response model with logit link, fractional response model with probit link and beta regression model, respectively.

Conclusions

This analysis describes the assessment of longitudinal approaches in modelling utility values and the four models proposed fitted the observed data well. Mapped utility values for patients treated with erenumab were generally higher than those for individuals treated with placebo with equivalent number of MMDs. Linking patient utility values to MMDs allows utility estimates for different levels of MMD to be predicted, for use in economic evaluations of preventive therapies.

Trial registration

ClinicalTrials.gov numbers of the trials used in this study: STRIVE, NCT02456740 (registered May 14, 2015), ARISE, NCT02483585 (registered June 12, 2015) and NCT02066415 (registered Feb 17, 2014).

Health state utilities associated with attributes of migraine preventive treatments based on patient and general population preferences

PURPOSE

While previous studies have estimated health state utilities associated with migraine severity and frequency, migraine treatments vary in other ways that may have an impact on patients' quality of life, preference, and utility. The purpose of this study was to estimate utilities associated with migraine treatment attributes including route of administration and treatment-related adverse events (AEs).

METHODS

In time trade-off interviews, migraine patients and general population participants in the UK valued health state vignettes drafted based on literature, medication labels, and clinician interviews. All respondents valued migraine health states varying in route of administration. Each participant also valued eight health states (randomly selected from a total of 15) that added the description of an AE to a migraine health state.

RESULTS

A total of 400 participants completed interviews (200 general population [49.0% female; mean age = 43.6 years]; 200 migraine patients [74.5% female; mean age = 45.8 years]). In the general population sample, mean utilities of health states without aura were 0.79 with daily oral medication, 0.78 with one injection per month, and 0.72 with 31-39 injections once every 3 months. The greatest disutilities (i.e., decreases in utility) were for AEs associated with oral medications (e.g., - 0.060 [fatigue] and - 0.098 [brain fog]). Differences among health states followed the same pattern in the patient sample as in the general population sample.

CONCLUSIONS

Utilities estimated from the general population sample may be used to represent route of administration and AEs in cost-utility models. Results from the patient sample indicate that these treatment characteristics have an impact on patient preference.

An Updated Systematic Review of Studies Mapping (or Cross-Walking) Measures of Health-Related Quality of Life to Generic Preference-Based Measures to Generate Utility Values

BACKGROUND

Mapping is an increasingly common method used to predict instrument-specific preference-based health-state utility values (HSUVs) from data obtained from another health-related quality of life (HRQoL) measure. There have been several methodological developments in this area since a previous review up to 2007.

OBJECTIVE

To provide an updated review of all mapping studies that map from HRQoL measures to target generic preference-based measures (EQ-5D measures, SF-6D, HUI measures, QWB, AQoL measures, 15D/16D/17D, CHU-9D) published from January 2007 to October 2018.

DATA SOURCES

A systematic review of English language articles using a variety of approaches: searching electronic and utilities databases, citation searching, targeted journal and website searches.

STUDY SELECTION

Full papers of studies that mapped from one health measure to a target preference-based measure using formal statistical regression techniques.

DATA EXTRACTION

Undertaken by four authors using predefined data fields including measures, data used, econometric models and assessment of predictive ability.

RESULTS

There were 180 papers with 233 mapping functions in total. Mapping functions were generated to obtain EQ-5D-3L/EQ-5D-5L-EQ-5D-Y (n = 147), SF-6D (n = 45), AQoL-4D/AQoL-8D (n = 12), HUI2/HUI3 (n = 13), 15D (n = 8) CHU-9D (n = 4) and QWB-SA (n = 4) HSUVs. A large number of different regression methods were used with ordinary least squares (OLS) still being the most common approach (used ≥ 75% times within each preference-based measure). The majority of studies assessed the predictive ability of the mapping functions using mean absolute or root mean squared errors (n = 192, 82%), but this was lower when considering errors across different categories of severity (n = 92, 39%) and plots of predictions (n = 120, 52%).

CONCLUSIONS

The last 10 years has seen a substantial increase in the number of mapping studies and some evidence of advancement in methods with consideration of models beyond OLS and greater reporting of predictive ability of mapping functions.

Cost-Effectiveness of Reclassifying Triptans in Australia: Application of an Economic Evaluation Approach to Regulatory Decisions

BACKGROUND

Migraine is a common, chronic, disabling headache disorder. Triptans, used as an acute treatment for migraine, are available via prescription in Australia. An Australian Therapeutic Goods Administration (TGA) committee rejected reclassifying sumatriptan and zolmitriptan from prescription medicine to pharmacist-only between 2005 and 2009, largely on the basis of concerns about patient risk. Nevertheless, pharmacist-only triptans may reduce migraine duration and free up healthcare resources.

OBJECTIVES

To estimate the cost-effectiveness of reclassifying triptans from prescription-only to pharmacist-only in Australia.

METHODS

The study design included decision-analytic modeling combining data from various sources. Behavior before and after reclassification was estimated using medical practitioner and patient surveys and also administrative data. Health outcomes included migraine frequency and duration as well as adverse events (AEs) discussed by the TGA committee. Efficacy and AEs were estimated using randomized controlled trials and observational studies.

RESULTS

Reclassifying triptans will reduce migraine duration but increase AEs. This will result in 337 quality-adjusted life-years gained at an increased cost of A$5.9 million over 10 years for all Australian adults older than 15 years (19.6 million). The incremental cost-effectiveness ratio was estimated to be A$17 412/quality-adjusted life-year gained.

CONCLUSIONS

The incremental cost-effectiveness ratio is likely to be considered cost-effective by Australian decision makers. Serotonin syndrome, a key concern of the TGA committee, had little impact on the results. Further research is needed regarding pharmacist-only triptan use by migraineurs currently using over-the-counter medicines and by nonmigraineurs, the efficacy of triptans, and the risk of cardiovascular and cerebrovascular AEs and chronic headaches with triptans.

Cost-effectiveness analysis of erenumab for the preventive treatment of episodic and chronic migraine: Results from the US societal and payer perspectives

Objectives

To assess the cost-effectiveness of erenumab 140 mg (“erenumab”) for the prophylactic treatment of episodic migraine and chronic migraine.

Study design

A hybrid Monte Carlo patient simulation and Markov cohort model was constructed to compare erenumab to no preventive treatment or onabotulinumtoxinA among adult ( ≥ 18 years) patients with episodic migraine and chronic migraine who failed prior preventive therapy from the US societal and payer perspectives.

Methods

Patients entered the model one at a time and were assigned to a post-treatment monthly migraine day category based on baseline monthly migraine days and treatment effect. Using monthly cycles, patients were followed for 2 years and accumulated costs and utilities associated with their post-treatment monthly migraine days. The primary outcome included the incremental cost-effectiveness ratio presented as cost per quality-adjusted life year gained.

Results

With an annual drug price of erenumab of $6900, treatment with erenumab in the societal perspective ranges from a dominant strategy versus no preventive treatment among chronic migraine patients to an incremental cost-effectiveness ratio of $122,167 versus no preventive treatment among episodic migraine patients. When excluding indirect costs (i.e. payer perspective), the incremental cost-effectiveness ratios are cost-effective among chronic migraine patients ($23,079 and $65,720 versus no preventive treatment and onabotulinumtoxinA, respectively), but not among episodic migraine patients ($180,012 versus no preventive treatment). Model results were sensitive to changes in monthly migraine days, health utilities, and treatment costs.

Conclusion

The use of erenumab may be a cost-effective approach to preventing monthly migraine days among patients with chronic migraine versus onabotulinumtoxinA and no preventive treatment in the societal and payer perspectives, but is less likely to offer good value for money for those with episodic migraine, unless lost productivity costs are considered.

Estimating the clinical effectiveness and value-based price range of erenumab for the prevention of migraine in patients with prior treatment failures: a US societal perspective

BACKGROUND

Frequent migraine with four or more headache days per month is a common, disabling neurovascular disease. From a US societal perspective, this analysis models the clinical efficacy and estimates the value-based price (VBP) for erenumab, a fully human monoclonal antibody that inhibits the calcitonin gene-related peptide receptor.

METHODS

A Markov health state transition model was developed to estimate the incremental costs, quality-adjusted life-years (QALYs), and value-based price range for erenumab in migraine prevention. The model comprises "on preventive treatment", "off preventive treatment", and "death" health states across a 10-year time horizon. The evaluation compared erenumab to no preventive treatment in episodic and chronic migraine patients that have failed at least one preventive therapy. Therapeutic benefits are based on estimated changes in monthly migraine days (MMD) from erenumab pivotal clinical trials and a network meta-analysis of migraine studies. Utilities were estimated using previously published mapping algorithms. A VBP analysis was performed to identify maximum erenumab annual prices at willingness-to-pay (WTP) thresholds of $100,000-$200,000 per QALY. Estimates of VBP under different scenarios such as choice of different comparators, assumptions around inclusion of placebo effect, and exclusion of work productivity losses were also generated.

RESULTS

Erenumab resulted in incremental QALYs of 0.185 vs supportive care (SC) and estimated cost offsets due to reduced MMD of $8,482 over 10 years, with an average duration of treatment of 2.01 years. The estimated VBP at WTP thresholds of $100,000-$200,000 for erenumab compared to SC ranged from $14,238-$23,998. VBP estimates including the placebo effect and excluding work productivity ranged from $7,445-$13,809; increasing to $12,151-$18,589 with onabotulinumtoxinA as a comparator in chronic migraine.

CONCLUSION

Erenumab is predicted to reduce migraine-related direct and indirect costs, and increase QALYs compared to SC.

Assessing the impact of headaches and the outcomes of treatment: A systematic review of patient-reported outcome measures (PROMs)

Aims To critically appraise, compare and synthesise the quality and acceptability of multi-item patient reported outcome measures for adults with chronic or episodic headache. Methods Systematic literature searches of major databases (1980-2016) to identify published evidence of PROM measurement and practical properties. Data on study quality (COSMIN), measurement and practical properties per measure were extracted and assessed against accepted standards to inform an evidence synthesis. Results From 10,903 reviewed abstracts, 103 articles were assessed in full; 46 provided evidence for 23 PROMs: Eleven specific to the health-related impact of migraine (n = 5) or headache (n = 6); six assessed migraine-specific treatment response/satisfaction; six were generic measures. Evidence for measurement validity and score interpretation was strongest for two measures of impact, Migraine-Specific Quality of Life Questionnaire (MSQ v2.1) and Headache Impact Test 6-item (HIT-6), and one of treatment response, the Patient Perception of Migraine Questionnaire (PPMQ-R). Evidence of reliability was limited, but acceptable for the HIT-6. Responsiveness was rarely evaluated. Evidence for the remaining measures was limited. Patient involvement was limited and poorly reported. Conclusion While evidence is limited, three measures have acceptable evidence of reliability and validity: HIT-6, MSQ v2.1 and PPMQ-R. Only the HIT-6 has acceptable evidence supporting its completion by all "headache" populations.

Development of a transformation model to derive general population-based utility: Mapping the pruritus-visual analog scale (VAS) to the EQ-5D utility

RATIONALE, AIMS, AND OBJECTIVES

Although nonpreference-based disease-specific measures are widely used in clinical studies, they cannot generate utilities for economic evaluation. A solution to this problem is to estimate utilities from disease-specific instruments using the mapping function. This study aimed to develop a transformation model for mapping the pruritus-visual analog scale (VAS) to the EuroQol 5-Dimension 3-Level (EQ-5D-3L) utility index in pruritus.

METHODS

A cross-sectional survey was conducted with a sample (n = 268) drawn from the general population of South Korea. Data were randomly divided into 2 groups, one for estimating and the other for validating mapping models. To select the best model, we developed and compared 3 separate models using demographic information and the pruritus-VAS as independent variables. The predictive performance was assessed using the mean absolute deviation and root mean square error in a separate dataset.

RESULTS

Among the 3 models, model 2 using age, age squared, sex, and the pruritus-VAS as independent variables had the best performance based on the goodness of fit and model simplicity, with a log likelihood of 187.13. The 3 models had similar precision errors based on mean absolute deviation and root mean square error in the validation dataset. No statistically significant difference was observed between the mean observed and predicted values in all models.

CONCLUSIONS

In conclusion, model 2 was chosen as the preferred mapping model. Outcomes measured as the pruritus-VAS can be transformed into the EQ-5D-3L utility index using this mapping model, which makes an economic evaluation possible when only pruritus-VAS data are available.

Burden of allergic respiratory disease: a systematic review

This meta-analysis compared the health-related quality of life (HRQL) of patients with allergic rhinitis (AR) and/or allergic asthma (AA) caused by perennial house dust mite (HDM) versus AR and/or AA caused by seasonal pollen allergy. Following a systematic search, the identified studies used the disease-specific rhinitis quality of life questionnaire or generic instruments (SF-36 and SF-12). Summary estimates obtained by meta-analysis showed that HRQL in patients with perennial HDM allergy was significantly worse than that of patients with seasonal pollen allergy, when measured by both disease-specific and generic HRQL instruments, and was reflected by an impact on both physical and mental health. A systematic review of cost data on AR and AA in selected European countries demonstrated that the majority of the economic burden was indirectly caused by high levels of absenteeism and presenteeism; there was little or no evidence of increasing or decreasing cost trends. Increased awareness of the detrimental effects of AR and/or AA on patients’ HRQL and its considerable cost burden might encourage early diagnosis and treatment, in order to minimize the disease burden and ensure beneficial and cost-effective outcomes.

Mapping between 6 Multiattribute Utility Instruments

Background: Cost-utility analyses commonly employ a multiattribute utility (MAU) instrument to estimate the health state utilities, which are needed to calculate quality-adjusted life years. Different MAU instruments predict significantly different utilities, which makes comparison of results from different evaluation studies problematical. Aim: This article presents mapping functions (“crosswalks”) from 6 MAU instruments (EQ-5D-5L, SF-6D, Health Utilities Index 3 [HUI 3], 15D, Quality of Well-Being [QWB], and Assessment of Quality of Life 8D [AQoL-8D]) to each of the other 5 instruments in the study: a total of 30 mapping functions. Methods: Data were obtained from a multi-instrument comparison survey of the public and patients in 7 disease areas conducted in 6 countries (Australia, Canada, Germany, Norway, United Kingdom, and United States). The 8022 respondents were administered each of the 6 study instruments. Mapping equations between each instrument pair were estimated using 4 econometric techniques: ordinary least squares, generalized linear model, censored least absolute deviations, and, for the first time, a robust MM-estimator. Results: Goodness-of-fit indicators for each of the results are within the range of published studies. Transformations reduced discrepancies between predicted utilities. Incremental utilities, which determine the value of quality-related health benefits, are almost perfectly aligned at the sample means. Conclusion: Transformations presented here align the measurement scales of MAU instruments. Their use will increase confidence in the comparability of evaluation studies, which have employed different MAU instruments.

The cost effectiveness of Botox in Italian patients with chronic migraine

Migraine is a primary headache which World Health Organization ranks in 19th place in the list of disabling diseases. In Europe, in 2004, the total costs for migraine were quantified by Stovner and Berg, Eur J Neurol, 12(s1) (2005) at <euro>27 billion. The objective of this study is to provide an estimate of the incremental cost-effectiveness ratio (ICER) of the treatment of chronic migraine with Botox compared to treatment with placebo in the perspective of the Italian National Health Service and society. To do this we studied the disease progression in a cohort of 688 individuals (patients enrolled in the study PREEMPT) via the application of a Markov model. Over a period of 2 years, the total costs of the experimental arm of the model amounted to <euro>3,274 compared with a gain of 1.34 QALYs. In contrast, the costs of the control arm amounted to <euro>2,395 with a gain of 1.24 QALYs. It follows that the incremental costs amounted to <euro>889 compared to an incremental gain of 0.09 QALYs in favor of the experimental arm. The relationship between costs and incremental QALYs generated an ICER of <euro>9,407/QALY. The incremental cost-effectiveness ratio, therefore, is favorable compared to the value usually considered by NICE as a threshold limit for reimbursement which ranges between <euro>20,000 and <euro>40,000/QALY.

Use of Bayesian multivariate meta-analysis to estimate the HAQ for mapping onto the EQ-5D questionnaire in rheumatoid arthritis

BACKGROUND

In health technology assessment, decisions about reimbursement for new health technologies are largely based on effectiveness estimates. Sometimes, however, the target effectiveness estimates are not readily available. This may be because many alternative instruments measuring these outcomes are being used (and not all always reported) or an extended follow-up time of clinical trials is needed to evaluate long-term end points, leading to the limited data on the target clinical outcome. In the areas of highest priority in health care, decisions are required to be made on a short time scale. Therefore, alternative clinical outcomes, including surrogate end points, are increasingly being considered for use in evidence synthesis as part of economic evaluation.

OBJECTIVE

To illustrate the potential effect of reduced uncertainty around the clinical outcome on the utility when estimating it from a multivariate meta-analysis.

METHODS

Bayesian multivariate meta-analysis has been used to synthesize data on correlated outcomes in rheumatoid arthritis and to incorporate external data in the model in the form of informative prior distributions. Estimates of Health Assessment Questionnaire were then mapped onto the health-related quality-of-life measure EuroQol five-dimensional questionnaire, and the effect was compared with mapping the Health Assessment Questionnaire obtained from the univariate approach.

RESULTS

The use of multivariate meta-analysis can lead to reduced uncertainty around the effectiveness parameter and ultimately uncertainty around the utility.

CONCLUSIONS

By allowing all the relevant data to be incorporated in estimating clinical effectiveness outcomes, multivariate meta-analysis can improve the estimation of health utilities estimated through mapping methods. While reduced uncertainty may have an effect on decisions based on economic evaluation of new health technologies, the use of short-term surrogate end points can allow for early decisions. More research is needed to determine the circumstances under which uncertainty is reduced.

Eliciting health state utilities for Dupuytren's contracture using a discrete choice experiment

BACKGROUND AND PURPOSE

An internet-based discrete choice experiment (DCE) was conducted to elicit preferences for a wide range of Dupuytren's contracture (DC)-related health states. An algorithm was subsequently developed to convert these preferences into health state utilities that can be used to assess DC's impact on quality of life and the value of its treatments.

METHODS

Health state preferences for varying levels of DC hand severity were elicited via an internet survey from a sample of the UK adult population. Severity levels were defined using a combination of contractures (0, 45, or 90 degrees) in 8 proximal interphalangeal and metacarpophalangeal joints of the index, middle, ring, and little fingers. Right-handed, left-handed, and ambidextrous respondents indicated which hand was preferable in each of the 10 randomly-selected hand-pairings comparing different DC severity levels. For consistency across comparisons, anatomically precise digital hand drawings were used. To anchor preferences onto the traditional 0-1 utility scale used in health economic evaluations, unaffected hands were assigned a utility of 1.0 whereas the utility for a maximally affected hand (i.e., all 8 joints set at 90 degrees of contracture) was derived by asking respondents to indicate what combination of attributes and levels of the EQ-5D-5L profile most accurately reflects the impact of living with such hand. Conditional logistic models were used to estimate indirect utilities, then rescaled to the anchor points on the EQ-5D-5L.

RESULTS

Estimated utilities based on the responses of 1,745 qualified respondents were 0.49, 0.57, and 0.63 for completely affected dominant hands, non-dominant hands, or ambidextrous hands, respectively. Utility for a dominant hand with 90-degree contracture in t h e metacarpophalangeal joints of the ring and little fingers was estimated to be 0.89. Separately, reducing the contracture of metacarpophalangeal joint for a little finger from 50 to 12 degrees would improve utility by 0.02.

INTERPRETATION

DC is associated with substantial utility decrements. The algorithms presented herein provide a robust and flexible framework to assess utility for varying degrees of DC severity.

Generic preference-based measures: how economists measure health benefit

Resources are always scarce, but the possible uses of these resources are limitless. This simple observation underlies much of what economists do. It leads to competing demands from different parties and requires individuals and organisations to make choices about their use of scarce resources. The primary purpose of economics is to help us understand how decisions about the distribution of scarce resources are made and to identify optimal decisions. It shouldn’t take too much of an intellectual leap to see how adopting an economist’s perspective might contribute to the improvement of patient care and health outcomes. The process of evaluating health care interventions is well-established, with the randomised controlled trial maintaining its place as the gold standard method. A crucial decision that must be made in figuring out if an intervention works is which indicator should be used. The purpose of the intervention might be to reduce mortality, improve functioning or prevent falls. It could be all three. If the intervention produces an improvement in these indicators it is probably of value – but of what value? How do we value this intervention? And why might we want to?

The cost-effectiveness of onabotulinumtoxinA for the prophylaxis of headache in adults with chronic migraine in the UK

BACKGROUND

Although chronic migraine is associated with substantial disability and costs, few treatments have been shown to be effective. OnabotulinumtoxinA (Botox, Allergan Inc., Irvine, CA) is the first treatment to be licensed in the UK for the prophylaxis of headaches in adults with chronic migraine. This study aims to evaluate the cost-effectiveness of onabotulinumtoxinA in this indication in the UK.

METHODS

A state-transition (Markov) model was developed comparing onabotulinumtoxinA to placebo. Efficacy data and utility values were taken from the pooled Phase III REsearch Evaluating Migraine Prophylaxis Therapy (PREEMPT) clinical trials program (n = 1384). Estimates of resource utilisation were taken from the International Burden of Migraine Study (IBMS), and stopping rules were informed by published medical guidelines and clinical data. This study estimated 2-year discounted costs and quality-adjusted life years (QALYs) from the UK National Health Service perspective.

RESULTS

At 2 years, treatment with onabotulinumtoxinA was associated with an increase in costs of £1367 and an increase in QALYs of 0.1 compared to placebo, resulting in an incremental cost-effectiveness ratio (ICER) of £15,028. Treatment with onabotulinumtoxinA reduced headache days by an estimated 38 days per year at a cost of £18 per headache day avoided. Sensitivity analysis showed that utility values had the greatest influence on model results. The ICER remained cost-effective at a willingness to pay threshold of £20,000-£30,000/QALY in the majority of scenario analyses as well as in probabilistic sensitivity analysis, where onabotulinumtoxinA was cost-effective on 96% of occasions at a threshold of £20,000/QALY and 98% of occasions at £30,000/QALY.

CONCLUSION

OnabotulinumtoxinA has been shown to reduce the frequency of headaches in patients with chronic migraine and can be considered a cost-effective use of resources in the UK National Health Service. The uncertainties in the model relate to the extrapolation of clinical data beyond the 56-week trial.