Economic evaluation of tiotropium and salmeterol in the treatment of chronic obstructive pulmonary disease (COPD) in Greece

Objective: The objective of the study was to assess the cost-effectiveness of two therapeutic alternatives for chronic obstructive pulmonary disease in the Greek National Health Service (NHS) setting. Methods: A Markov probabilistic model was used to compare tiotropium with salmeterol. A Monte Carlo simulation with 5000 cases was run in the probabilistic analysis. The model was designed to compute the expected time spent in each state, the expected number of exacerbations occurring and the expected treatment cost per patient. Probabilities were extracted from clinical trials, resource utilisation and cost data from a Greek university hospital. Results: Quality adjusted life years were 0.70 ( 95% Uncertainty Interval [UI]: 0.63 to 0.77) in the tiotropium arm and 0.68 (95% UI: 0.60 to 0.75) in the salmeterol arm; a difference of 0.02 (95% UI: - 0.08 to 0.13). Exacerbations reached 0.85 (95% UI: 0.80 to 0.91) in the tiotropium arm and 1.02 (95% UI: 0.84 to 1.21) in the salmeterol arm, a difference of -0.17 (95% UI: -0.37 to 0.02). Estimates of the mean annual cost per patient were EURO2504 (EURO2122 to EURO2965) in the tiotropium arm and EUEO2655 (EURO2111 to EURO3324) in the salmeterol arm, a difference of -EURO151 (-EURO926 to EURO580). Stochastic analysis showed that tiotropium may have an advantage in reducing exacerbations. The probability that tiotropium is cost-effective was 65% at a ceiling value of EURO0 and reached 77% at a ceiling ratio of EURO1000. Results stay fairly constant in various sensitivity analyses. Conclusion: Even though tiotropium is more expensive to buy than salmeterol in the Greek NHS (using Greek costs there was no statistically significant difference in total costs between tiotropium and salmeterol), overall, during the course of a year, it is actually associated with a lower prevalence of exacerbations and lower treatment costs and thus may represent a viable and cost-effective alternative in the Greek NHS setting.