Clinical and economic impact of non-adherence in COPD: a systematic review.
BACKGROUND
Medication for Chronic Obstructive Pulmonary Disease (COPD) has shown to substantially reduce symptoms and slow progression of disease. However, non-adherence to medication is common and associated with worsened clinical and economic outcomes.


OBJECTIVE
The objective of this study was to perform a systematic review of published literature to assess the impact of non-adherence to COPD medication on clinical and economic outcomes.


METHODS
A search in PubMed and Web of Science databases was conducted of original studies published from database inception to 2012. Studies must report on the association between adherence to COPD medication and outcomes, published in English in peer-reviewed journals and full texts needed to be available.


RESULTS
Twelve full articles were included in the review. Most studies were retrospective database studies. Seven studies reported on the association between adherence and clinical outcomes, two on mortality, three on costs, four on quality of life and one on work productivity. Results indicated a clear association between adherence and both clinical and economic outcomes. Evidence from studies revealed increased hospitalizations, mortality, quality of life and loss of productivity among non-adherent patients.


CONCLUSION
This review revealed a clear association between non-adherence to COPD medication and worsened clinical and economic outcomes making non-adherent patients a priority for cost-effective interventions.