Economic analyses comparing tiotropium with ipratropium or salmeterol in UK patients with COPD
Aims: This study presents a cost-effectiveness and budget impact analysis comparing cost and outcomes for UK patients with COPD treated with either tiotropium, ipratropium or salmeterol. Methods: A previously-published COPD cost-effectiveness model was adapted for the UK, then used to estimate the cost-effectiveness of tiotropium compared to salmeterol and ipratropium. Additional epidemiological data were used to estimate the budget impact of switching patients from ipratropium or salmeterol to tiotropium. Results: In England, the estimated annual cost per patient on tiotropium was £1350, on salmeterol was £1404, and on ipratropium was £1427; in Scotland/Wales/Northern Ireland (S/W/NI) these costs were £1439, £1565, and £1631, respectively. Tiotropium patients experienced better quality-adjusted life-years (QALYs) across all comparisons, and this option was therefore dominant compared to salmeterol and ipratropium. The probability of tiotropium being dominant ranged from 72% to 87% across comparisons. At a willingness-to-pay threshold of £20,000 per QALY, tiotropium had at least a 97% chance of being cost-effective. The estimated annual saving per primary care trust (PCT) of switching patients from salmeterol and ipratropium to tiotropium in England was £230,000 and in S/W/NI was £160,000. Conclusions: Tiotropium is a cost-effective alternative to ipratropium and salmeterol, and switching COPD patients from ipratropium and salmeterol to tiotropium could result in considerable cost savings for PCTs along with improvements in quality-of-life.