Adherence to Medication and Its Impact on Chronic Obstructive Pulmonary Disease (COPD) Exacerbations: The AMICE Prospective Study

Chronic Obstructive Pulmonary Disease (COPD) represents one of the most challenging chronic diseases of the 21st century: it is expected to be the fourth leading cause of death by 2030. COPD is characterized by pulmonary and extra-pulmonary systemic manifestations caused by partly irreversible expiratory airflow obstruction. The cornerstone of COPD management is the prescription of single or combined inhalation therapy, such as short- and long-acting bronchodilators, inhaled corticosteroids to possibly prevent disease progression, preserve lung function, relieve respiratory symptoms and prevent or treat exacerbations. Given the complex and lifelong treatment, one can expect that adherence to the prescribed inhalation therapy is not self-evident. Adherence can be defined as the "the extent to which a person's behaviour (taking medications, following a recommended diet and/or executing life-style changes) corresponds with the agreed recommendations of a health care provider". Inhaled medications have an additional complexity in that patients who intend to be adherent may be take the inhaled medication incorrectly, prohibiting proper therapeutic action. Taking less than the prescribed amount of medication, missing doses or stopping treatment for brief or extended periods will put the patient at risk for suboptimal disease control. Hence, the effectiveness will largely depend on the patient's ability to manage their disease adequately in daily life. Using electronic monitoring, 3 studies in COPD found a prevalence of medication non-adherence of 51% which was worse than the average prevalence of 29% (range 3-66%) found across diseases such as hypertension, cancer, epilepsia, infections and HIV. The existing evidence on risk factors for nonadherence in COPD is mostly anecdotic and not guided by behavioral models. According to the integrated model of behavioral prediction (IMBP), barriers, skills and ability and intention are the most important drivers of adherence (i.e.