Patient preferences for dry powder inhaler attributes in asthma and chronic obstructive pulmonary disease in France: a discrete choice experiment.

BACKGROUND: Dry powder inhalers (DPIs) are often used in asthma and chronic obstructive pulmonary disease (COPD) therapies. Using the discrete choice experiment (DCE) methodology, this study conducted in France was designed to assess patients' preferences for different attributes of DPIs. METHODS: Attributes of DPIs were defined based on a literature review, patient focus group discussions and interviews with healthcare professionals (qualitative phase of the study). An online survey was then conducted among French patients with asthma or COPD to elicit patient preferences and willingness to pay (WTP) for these attributes using the DCE methodology (quantitative phase). A fractional factorial design including three blocks of 12 choice sets was created. Each choice set comprised three alternatives: two fictitious inhalers and the patient's current inhaler. Marginal utilities were estimated using a ranked ordered logit model. Interactions between attributes and disease (asthma or COPD) were tested. RESULTS: Six DPI attributes were defined based on the qualitative phase: ease of use/fool-proof priming; accurate and easy-to-read dose counter; dose confirmation; hygiene of the mouthpiece; flexibility of the device handling; ability to use the inhaler with breathing difficulties. Overall, 201 patients with asthma and 93 with COPD were included in the online survey. Patients with asthma placed most value on an inhaler that requires one step for dose preparation (WTP €4.83 [95% CI: €3.77-€5.90], relative to an inhaler requiring four steps) and one that could be used during episodes of breathing difficulties (WTP €4.49 [95% CI: €2.95-€6.02]). Patients with COPD placed most value on an inhaler that could be used during episodes of breathing difficulties (WTP €7.70 [95% CI: €5.65-€9.76]) and on the accuracy of the dose counter (WTP €5.87 [95% CI: €3.98-€ 7.77]). CONCLUSION: This study suggests that asthma and COPD patients would be willing to change their inhaler if they were offered the option of a new inhaler with improved characteristics and they place a high value on an inhaler with ease of use during breathing difficulty episodes.

Cost-Effectiveness of Mirabegron Compared with Antimuscarinic Agents for the Treatment of Adults with Overactive Bladder in the United Kingdom.

BACKGROUND: Mirabegron, a first-in-class selective oral ß3-adrenoceptor agonist, has similar efficacy to most antimuscarinic agents and a lower incidence of dry mouth in patients with overactive bladder (OAB). OBJECTIVES: To evaluate the cost-effectiveness of mirabegron 50 mg compared with oral antimuscarinic agents in adults with OAB from a UK National Health Service perspective. METHODS: A Markov model including health states for symptom severity, treatment status, and adverse events was developed. Cycle length was 1 month, and the time horizon was 5 years. Antimuscarinic comparators were tolterodine extended release, solifenacin, fesoterodine, oxybutynin extended release and immediate release (IR), darifenacin, and trospium chloride modified release. Transition probabilities for symptom severity levels and adverse events were estimated from a mirabegron trial and a mixed treatment comparison. Estimates for other inputs were obtained from published literature or expert opinion. Quality-adjusted life-years (QALYs) and total health care costs, including costs of drug acquisition, physician visits, incontinence pad use, and botox injections, were modeled. Deterministic and probabilistic sensitivity analyses were performed. RESULTS: Base-case incremental cost-effectiveness ratios ranged from £367 (vs. solifenacin 10 mg) to £15,593 (vs. oxybutynin IR 10 mg) per QALY gained. Probabilistic sensitivity analyses showed that at a willingness-to-pay threshold of £20,000/QALY gained, the probability of mirabegron 50 mg being cost-effective ranged from 70.2% versus oxybutynin IR 10 mg to 97.8% versus darifenacin 15 mg. A limitation of our analysis is the uncertainty due to the lack of direct comparisons of mirabegron with other agents; a mixed treatment comparison using rigorous methodology provided the data for the analysis, but the studies involved showed heterogeneity. CONCLUSIONS: Mirabegron 50 mg appears to be cost-effective compared with standard oral antimuscarinic agents for the treatment of adults with OAB from a UK National Health Service perspective.

Comparative efficacy and safety of medical treatments for the management of overactive bladder: a systematic literature review and mixed treatment comparison.

CONTEXT: Overactive bladder (OAB) treatment guidelines recommend antimuscarinics as first-line pharmacologic therapy. Mirabegron is a first-in-class ß3-adrenoceptor agonist licensed for the treatment of OAB and has shown to be well tolerated and effective in the treatment of OAB symptoms. OBJECTIVE: To assess the relative efficacy and tolerability of OAB medications, specifically mirabegron 50 mg versus antimuscarinics in patients with OAB. EVIDENCE ACQUISITION: A systematic literature search was performed on published peer-reviewed articles from 2000 to 2013. This review included randomised controlled trials (RCTs) studying changes in symptoms (micturition frequency, incontinence, and urgency urinary incontinence [UUI] episodes) and incidence of the most frequently reported adverse events (dry mouth, constipation) associated with current OAB medications. The following drugs were considered in addition to mirabegron: darifenacin, tolterodine immediate release (IR) and extended release (ER), oxybutynin IR/ER, trospium, solifenacin, and fesoterodine. Bayesian mixed treatment comparisons (MTCs) were performed for efficacy (micturition, incontinence, UUI) and tolerability (dry mouth, constipation, blurred vision). EVIDENCE SYNTHESIS: Overall, 44 RCTs involving 27,309 patients were included. The MTCs showed that mirabegron 50 mg was as efficacious as antimuscarinics in reducing the frequency of micturition incontinence and UUI episodes, with the exception of solifenacin 10 mg that was more efficacious than mirabegron 50 mg in improving micturition frequency and frequency of UUI. Mirabegron 50 mg had an incidence of dry mouth similar to placebo and significantly lower than all included antimuscarinics. CONCLUSIONS: Mirabegron 50 mg had similar efficacy to most antimuscarinics and lower incidence of dry mouth, the most common adverse event reported with antimuscarinics and one of the main causes of discontinuation of treatment. Despite being a powerful tool for evidence-based health care evaluation, the Bayesian MTC method has limitations. Further head-to-head comparisons between mirabegron and antimuscarinics should be conducted to confirm our results.