Predicting the outcomes and costs for a cohort of 426 patients with Chronic Obstructive Pulmonary Disease (COPD) in Bulgaria through a Markov model

Abstract

The aim was to estimate the economic burden, as well as rate of progression of COPD for a cohort of 426 patients for a 10-year period. A total of 426 patients from 19 regions with Chronic Obstructive Pulmonary Disease were enrolled in a representative, ambispective, national study for Bulgaria. Patients were recorded on disease stage, occupation, smoking habits and medication. Cost of treatment was calculated and a 10-year one-way Markov model was used by employing transition probabilities and quality of life data from available literature. Costs and outcomes were recorded and a cost-effectiveness acceptability curve (CEAC) was established. Out of all patients included in the study 288 were non-smokers with a mortality percentage after 10 years of 42.7%. Smokers showed faster transition rate with 139 of them transitioning to more severe states and mortality was 54.6%. The incremental cost-effectiveness ratio (ICER) was 863.75 BGN. Patients who smoked had a lower quality of life - cumulatively for the 10-year period QALY = 623.51 for smokers vs. 1557.51 for non-smokers, but also lower costs for treatment (538 007.52 BGN vs. 1 344 757.95 BGN) accounted by the high transition rate and mortality amongst that group. Relatively few non-smokers transitioned from a less severe to a more severe state (6%), while most of the very severe stage patients experienced a lethal outcome within 10 years (81%). Despite the higher costs associated with the disease, the Quality of Life and lower transition probability would enable patients to live a normal life. The ICER was well below the WHO threshold.