Improving inhaler adherence in patients with Chronic Obstructive Pulmonary Disease: a cost-effectiveness analysis

Background: The PHARMACOP-intervention significantly improved medication adherence and inhalation technique for patients with COPD compared with usual care. This study aimed to evaluate its cost-effectiveness. Methods: An economic analysis was performed from the Belgian healthcare payer's perspective. A Markov model was constructed in which a representative group of patients with COPD (mean age of 70 years, 66% male, 43% current smokers and mean Forced Expiratory Volume in 1 second of % predicted of 50), was followed for either receiving the 3-month PHARMACOP-intervention or usual care. Three types of costs were calculated: intervention costs, medication costs and exacerbation costs. Outcome measures included the number of hospital-treated exacerbations, cost per prevented hospital-treated exacerbation and cost per Quality Adjusted Life-Year. Follow-up was 1 year in the basecase analysis. Sensitivity and scenario analyses (including long-term follow-up) were performed to assess uncertainty. Results: In the basecase analysis, the average overall costs per patient for the PHARMACOP-intervention and usual care were epsilon 2,221 and epsilon 2,448, respectively within the 1-year time horizon. This reflects cost savings of epsilon 227 for the PHARMACOP-intervention. The PHARMACOP-intervention resulted in the prevention of 0.07 hospital-treated exacerbations per patient (0.177 for PHARMACOP versus 0.244 for usual care). Results showed robust cost-savings in various sensitivity analyses. Conclusions: Optimization of current pharmacotherapy (e. g. close monitoring of inhalation technique and medication adherence) has been shown to be cost-saving and should be considered before adding new therapies.