Burden of illness, medication adherence, and unmet medical needs in Japanese patients with atopic dermatitis: A retrospective analysis of a cross-sectional questionnaire survey.

Atopic dermatitis (AD) negatively affects patients' daily lives. Poor medication adherence is a major barrier to treatment success. However, factors causing patients' poor adherence are unclear. This study aimed to identify factors associated with improvement of medication adherence in Japanese patients with AD and to evaluate illness burden and unmet medical needs for AD. We retrospectively analyzed Web-based questionnaire surveys conducted in 2018 in patients with AD aged 15 years and above who had been in- or outpatients within the past year from the survey. Quality of life using the EuroQol 5-Dimension (EQ-5D), and work productivity and activity impairment using Work Productivity and Activity Impairment Questionnaire (WPAI) were compared between patients and matched controls who had not visited a hospital for any disease within the past year. Subpopulation analysis was performed to explore factors affecting medication adherence. Unmet medical needs in AD treatment were identified by the percentage of patients who rated issues on the questionnaire as important but who were unsatisfied with them. In this study, we identified 1739 patients with AD. The scores of EQ-5D and WPAI showed that patients had statistically lower quality of life and higher impairment of work and activities than controls. High medication adherence scores were seen in patients with high health literacy levels and those who were well satisfied with communication with health-care providers, information received from them, or explanations of AD. Current unmet medical needs for AD were medical treatment costs, ease of hospital visits and explanations about disease prognosis. Patients tended to put a higher priority on communication with physicians than on that with nurses and pharmacists. In conclusion, we have identified patients' higher health literacy levels and satisfaction with the communication with their health-care provider as potential factors to improve medication adherence.