Economic and humanistic impact of medication nonadherence in patients with asthma and chronic obstructive pulmonary disease.

摘要

Asthma and chronic obstructive pulmonary disease (COPD) significantly impact morbidity and mortality. In spite of the well-known benefits of prophylactic medication use, especially in asthma, the rate of medication nonadherence is more than 50%. In Phase I, this study examined the relationship between refill-based medication nonadherence and healthcare utilization/costs in patients with asthma, COPD, and those with both asthma and COPD from the West Virginia (WV) Public Employees Insurance Agency (PEIA) program. In Phase II, the study measured the relationship between refill-based and self-reported medication nonadherence, health-related quality of life (HRQL), and losses in workplace productivity, all of which were determined via a mailed questionnaire to patients identified from Phase I. Phase I Results: The prevalence of asthma in the study population was similar to national estimates (203/10,000), whereas the prevalence of COPD was higher (598/10,000). Among asthma-only and those with both asthma and COPD, more than half the patients received medications according to NHLBI guidelines. Refill-based medication adherence was highest in patients having both asthma and COPD, as compared to asthma-only or COPD-only enrollees. The number of adverse outcomes such as hospitalizations and ED visits increased with increasing refill-based adherence for the COPD-only patients. Total healthcare costs increased with increasing medication adherence for all three groups. Thus, increasing medication adherence was possibly a reflection of increasing disease severity. Phase II Results: The overall response rate was almost 23% (N = 918), and was highest for the asthma-only group (25%), followed by the 'both' group (24%), and the COPD-only group (15%). The perception of HRQL among WV PEIA enrollees was similar to those found in other studies. Only 40% of all Phase II respondents reported themselves as high adherent; the prevalence of self-reported adherence being similar in all three sub-groups. The correlations between self-reported and refill-based adherence in the three groups were not clinically significant. Medication adherence was a significant predictor of HRQL for the COPD-only group, with HRQL worsening with increasing adherence. Self-reported health status was a significant predictor of HRQL for each of the three disease groups; and HRQL worsened with deteriorating health status. In all three groups, medication adherence was not significantly associated with losses in workplace productivity dollars.