Cost-effectiveness analysis of tiotropium bromide and salmeterol in the treatment of severe chronic opstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation that is not fully reversible. The airflow limitation is usually both progressive and associated with an abnormal inflammatory response of the lungs to noxious particles or gases. Airflow limitation is associated with symptoms of chronic cough, expectoration, and dyspnea on effort. The objective of this pharmacoeconomic study was to examine and compare the cost-effectiveness ratio of tiotropium bromide and salmeterol in the treatment of severe COPD. The analysis was conducted using Markov model, based on data from the literature about the effectiveness and cost calculations from the perspective of the National Health Insurance Fund in Serbia. Effects for each condition are expressed in quality-adjusted life years (QALYs). The model was simulated using Monte Carlo method, for 1000 hypothetical patients. The time horizon was set at five years (60 cycles). The duration of each cycle was one month. The sensitivity analysis was performed with a variation of parameter values by ± 50% and presented by tornado diagram. The results of Monte Carlo simulations demonstrated small difference between these two drugs. Tiotropium bromide was more cost-effective option than salmeterol, ie. 76.873,80 RSD/QALY vs. 77.252,15 RSD/QALY. The results of this study show that use of tiotropium bromide is more useful option for the treatment of severe COPD (stage III), because greater clinical effectiveness is achieved with a little higher cost of treatment compared with salmeterol