Objective: This study was undertaken to examine the impact of select demographic, clinical, and medication-related factors on elderly patients' medication adherence to inhaled corticosteroid therapy. It also examined the impact of medication adherence on health outcomes and on health care service utilization and costs.
Background: Asthma in the elderly is a growing concern because of its increasing prevalence and the increase in asthma-related deaths. Poor medication utilization could be contributing to this trend in the elderly population and should be examined.
Methods: This retrospective, longitudinal, 2-year cohort study included 1595 patients aged > or =65 years with moderate to severe chronic pulmonary disease who were enrolled in a health maintenance organization. The study used sequential regression analyses to model (1) medication adherence and (2) health care service utilization and charges as functions of adherence.
Results: With other factors controlled for, this study found that clinical and medication-related variables including comorbidities, additional complications, and number of medications were predictive of adherence to prophylactic inhaled corticosteroid therapy in this population. Poorer medication adherence was associated with a 5% increase in total annual physician visits (P < 0.05). Better medication adherence was associated with a 20% decrease in annual hospitalization (P < 0.05). Additional pulmonary complications and severe comorbidities were associated with increases in health care utilization and costs. Patients with better adherence to prophylactic therapy were few, and the beneficial effects of better adherence were not significant when the population averages were considered.
Conclusions: The results of this study indicated that the beneficial effects of better adherence to prophylactic inhaled corticosteroid therapy tended to diminish in a population with relatively poor medication adherence. Findings of this study support a policy of selectively targeting elderly patients at risk for morbidity and implementing monitoring, education, and management programs to increase medication-adherence behavior. This policy could lead to optimal resource utilization and management of chronic pulmonary disease.