Factors Related to Treatment Non-Adherence Among Caregivers of Pediatric and Adolescent Growth Hormone Deficiency Patients in Japan

Background: About one-third of caregivers of pediatric or adolescent growth hormone deficiency (pGHD) patients in Japan have reported poor treatment adherence. However, few studies have examined factors related to adherence for that group. Objective: The aim of this study is to consider factors related to poor adherence to daily treatment among caregivers of pGHD patients in Japan. Methods: A cross-sectional survey was conducted among caregivers of pGHD patients in Japan. Caregivers were asked about demographic and treatment characteristics, health literacy, treatment satisfaction, opinions about treatment, and treatment adherence. Health literacy was assessed using the 14-item health literacy scale (HLS-14). Adherence was assessed using the 8-item Morisky Medication Adherence Scale (MMAS-8). Statistical association with adherence was considered using Chi-square and Student's t- testing. An exploratory factor analysis (EFA) and K-means cluster analysis was conducted to consider the influence of treatment satisfaction and opinions concerning treatment on adherence. Results: Responses were collected from 112 caregivers. The caregiver's age being 30-39 years old, the primary caregiver being male, the primary caregiver being employed, and low functional health literacy for the caregiver were associated with poor adherence. Patients being pre-elementary school age was also associated with poor adherence. Low satisfaction with drug treatment and/or their device and communication with healthcare professionals (HCPs), and lack of agreement with the importance of treatment management (eg, keeping injection records, getting informed about the disease/therapy, reporting non-adherence, and sticking to an administration schedule), were also associated with poor adherence. Conclusion: Strategies to improve treatment adherence among caregivers of pGHD patients in Japan should consider the age, gender, and employment status of the caregiver - as well as their functional literacy. Improvement in satisfaction with the drug or device used, better communication with HCPs, and greater awareness of the importance of treatment management, may also lead to better adherence.