Cost Effectiveness of Leukotriene Receptor Antagonists versus Long-Acting Beta-2 Agonists as Add-On Therapy to Inhaled Corticosteroids for Asthma
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Background: Information is lacking on the relative effectiveness and cost effectiveness — in a real-life primary-care setting — of leukotriene receptor antagonists (LTRAs) and long-acting β2 adrenergic receptor agonists (β2 agonists) as add-on therapy for patients whose asthma symptoms are not controlled on low-dose inhaled corticosteroids (ICS).
Objective: To estimate the cost effectiveness of LTRAs compared with longacting β2 agonists as add-on therapy for patients whose asthma symptoms are not controlled on low-dose ICS.
Methods: An economic evaluation was conducted alongside a 2-year, pragmatic, randomized controlled trial set in 53 primary-care practices in the UK. Patients aged 1280 years with asthma insufficiently controlled with ICS (n = 361) were randomly assigned to add-on LTRAs (n = 176) or long-acting β2 agonists (n = 185). The main outcome measures were the incremental cost per point improvement in the Mini Asthma Quality of Life Questionnaire (MiniAQLQ), per point improvement in the Asthma Control Questionnaire (ACQ) and per QALY gained from perspectives of the UK NHS and society.
Results: Over 2 years, the societal cost per patient receiving LTRAs was £1157 versus £952 for long-acting b2 agonists, a (significant, adjusted) increase of d214 (95%CI 2, 411) [year 2005 values]. Patients receiving LTRAs experienced a non-significant incremental gain of 0.009 QALYs (95% CI −0.077, 0.103). The incremental cost per QALY gained from the societal (NHS) perspective was £22 589 (£11 919). Uncertainty around this point estimate suggested that, given a maximum willingness to pay of £30 000 per QALY gained, the probability that LTRAs are a cost-effective alternative to long-acting β2 agonists as add-on therapy was approximately 52% from both societal and NHS perspectives.
Conclusions: On balance, these results marginally favour the repositioning of LTRAs as a cost-effective alternative to long-acting β2 agonists as add-on therapy to ICS for asthma. However, there is much uncertainty surrounding the incremental cost effectiveness because of similarity of clinical benefit and broad confidence intervals for differences in healthcare costs.
Trial registration: UK National Research Register N0547145240; Controlled Clinical Trials ISRCTN99132811.
The authors thank all the patients and their families for their participation and support during the study. We gratefully acknowledge the support and assistance of many who have helped this study, including GPs, nurses and administrative staff in the participating practices; Julie Houghton, Emma Koro, Sasha Rust-Andrews and Carole Bull of the research team; Dr Alistair Lipp for advice on study design and delivery; Dr Mark L. Levy (Clinical Research Fellow: Allergy & Respiratory Research Group, Division of Community Health Sciences, University of Edinburgh) for advice on the initial study design and implementation; Jon Bell for advice on peak flow measurement; and Linda Kemp of Respiratory Research Ltd for assistance with the analyses.
This project was funded by the Health Technology Assessment Programme (project number 98/34/05). The views and opinions expressed herein are those of the authors and do not necessarily reflect those of the Department of Health (UK). Additional support was provided for the implementation of the study from Clement-Clarke International and by unrestricted educational grants from Merck Sharpe and Dohme Ltd, AstraZeneca Ltd and Respiratory Research Ltd, who contributed 9% of the total budget.
For a list of the contributions of the authors to the study and their conflicts of interest, see the Supplemental Digital Content 2, http://links.adisonline.com/PCZ/A79.
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