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

ABSTRACT

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 €2504 (€2122 to €2965) in the tiotropium arm and €2655 (€2111 to €3324) in the salmeterol arm, a difference of –€151 (–€926 to €580). 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 €0 and reached 77% at a ceiling ratio of €1000. 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.

Key words: :

• Chronic obstructive pulmonary disease (COPD)
• Economic evaluation
• Greece
• Salmeterol
• Tiotropium

Notes

* Part of this material was presented as poster at the 8th Annual European Congress of the International Society of Pharmacoeconomics and Outcomes Research (ISPOR), Florence, 6–8 November, 2005