Cost effectiveness of pharmacological maintenance treatment for chronic obstructive pulmonary disease: a review of the evidence and methodological issues.

backgroundOver 200 million people have chronic obstructive pulmonary disease (COPD) worldwide. The number of disease-year equivalents and deaths attributable to COPD are high. Guidelines for the pharmacological treatment of the disease recommend an individualized step-up approach in which treatment is intensified when results are unsatisfactory.

objectiveOur objective was to present a systematic review of the cost effectiveness of pharmacological maintenance treatment for COPD and to discuss the methodological strengths and weaknesses of the studies.

methodsA systematic literature search for economic evaluations of drug therapy in COPD was performed in MEDLINE, EMBASE, the Economic Evaluation Database of the UK NHS (NHS-EED) and the European Network of Health Economic Evaluation Databases (EURONHEED). Full economic evaluations presenting both costs and health outcomes were included.

resultsA total of 40 studies were included in the review. Of these, 16 were linked to a clinical trial, 14 used Markov models, eight were based on observational data and two used a different approach. The few studies on combining short-acting bronchodilators were consistent in finding net cost savings compared with monotherapy. Studies comparing inhaled corticosteroids (ICS) with placebo or no maintenance treatment reported inconsistent results. Studies comparing fluticasone with salmeterol consistently found salmeterol to be more cost effective. The cost-effectiveness studies of tiotropium versus placebo, ipratropium or salmeterol pointed towards a reduction in total COPD-related healthcare costs for tiotropium in many but not all studies. All of these studies reported additional health benefits of tiotropium. The cost-effectiveness studies of the combination of inhaled long-acting β₂-agonists and ICS all report additional health benefits at an increase in total COPD-related costs in most studies. The cost-per-QALY estimates of this combination treatment vary widely and are very sensitive to the assumptions on mortality benefit and time horizon.

conclusionsThe currently available economic evaluations indicate differences in cost effectiveness between COPD maintenance therapies, but for a more meaningful comparison of results it is important to improve the consistency with respect to study methodology and choice of comparator.