Cost-effectiveness of tiotropium versus salmeterol: the POET-COPD trial

The aim of this study was to perform a 1-yr trial-based cost-effectiveness analysis (CEA) of tiotropium versus salmeterol followed by a 5-yr model-based CEA. The within-trial CEA, including 7,250 patients with moderate to very severe chronic obstructive pulmonary disease (COPD), was performed alongside the 1-yr international randomised controlled Prevention of Exacerbations with Tiotropium (POET)-COPD trial comparing tiotropium with salmeterol regarding the effect on exacerbations. Main end-points of the trial-based analysis were costs, number of exacerbations and exacerbation days. The model-based analysis was conducted to extrapolate results to 5 yrs and to calculate quality-adjusted life years (QALYs). 1-yr costs per patient from the German statutory health insurance (SHI) perspective and the societal perspective were €126 (95% uncertainty interval (UI) €55-195) and €170 (95% UI €77-260) higher for tiotropium, respectively. The annual number of exacerbations was 0.064 (95% UI 0.010-0.118) lower for tiotropium, leading to a reduction in exacerbation-related costs of €87 (95% UI €19-157). The incremental cost-effectiveness ratio was €1,961 per exacerbation avoided from the SHI perspective and €2,647 from the societal perspective. In the model-based analyses, the 5-yr costs per QALY were €3,488 from the SHI perspective and €8,141 from the societal perspective. Tiotropium reduced exacerbations and exacerbation-related costs, but increased total costs. Tiotropium can be considered cost-effective as the resulting cost-effectiveness ratios were below commonly accepted willingness-to-pay thresholds.