Background: Healthcare costs for chronic obstructive pulmonary disease (COPD) have continued to increase with the increasing prevalence of the disease. New interventions that can reduce the medical costs of COPD are needed. Tiotropium bromide, a once-daily inhaled anticholinergic, has been evaluated in patients with COPD enrolled in two 1-year randomised, double-blind, placebo-controlled (usual care) trials which showed the drug reduced exacerbations and improved spirometry, dyspnoea, and health status.
Objective: To retrospectively assess the direct costs of medical care for COPD in a US healthcare setting for patients treated with tiotropium in addition to usual care compared with usual care alone over a 1-year timeframe. The study was based on resource utilisation in the two previously described trials.
Methods: Resource utilisation and clinical data were prospectively collected for the two 1-year, randomised, double-blind trials of tiotropium plus usual care versus usual care alone (placebo) in 921 patients with COPD. Usual care was defined as any medication for COPD used prior to the trial except anticholinergics and long-acting beta-adrenoceptor agonists. Medical care resource utilisation was recorded at every scheduled visit in each trial. Mean total costs were calculated retrospectively by combining the resources utilised with the appropriate unit costs (1999 US dollars), excluding study drug (tiotropium) costs.
Results: Compared with usual care, patients receiving tiotropium in addition to usual care had significantly fewer COPD exacerbations (20% decrease), hospitalisations (44% reduction) and hospital days (50% reduction). Utilisation of resources other than hospitalisation did not differ between study groups. As a consequence, patients receiving tiotropium had significantly lower mean per- patient costs of hospitalisation compared with patients receiving usual care alone (tiotropium US 1,738 dollars +/- US 259 dollars; placebo US 2,793 dollars +/- US 453 dollars). The mean difference in the cost of hospitalisation (resulting from all causes, including COPD) between treatment groups was -US 1,056 dollars (95% CI -US 2,078 dollars, -US 34 dollars), and the difference in total healthcare costs (excluding study drug acquisition cost) was -US 1,043 dollars (95% CI -US 2,136 dollars, US 48 dollars) in favour of tiotropium. The cost of hospital admissions accounted for 48% of the total direct medical costs in this trial.
Conclusions: As hospitalisation is a large contributor to the cost of COPD, the addition of tiotropium to usual care therapy may have the potential to reduce the economic burden of COPD in a US healthcare setting. However, as our study did not consider the acquisition cost of tiotropium, further economic evaluation including this cost is needed to address whether tiotropium is cost saving compared with usual care (placebo).