Abstract
Background: Medication adherence among older adults with chronic conditions remains suboptimal, contributing to adverse health outcomes. Patient portals offer potential to improve adherence through enhanced communication and medication management, but evidence specific to older populations is limited. Methods: A convergent mixed-methods design was employed. Quantitative data were collected from 342 older adults (≥65 years) with at least one chronic condition who had access to a patient portal. Medication adherence was measured using the Morisky Medication Adherence Scale (MMAS-8). Portal usage metrics were extracted from system logs. Qualitative semi-structured interviews were conducted with 20 participants to explore experiences and barriers. Multivariable linear regression examined associations between portal use and adherence, controlling for demographics, health literacy, and comorbidity. Thematic analysis was applied to qualitative data. Results: Mean adherence score was 6.8 (SD=1.5). Portal features most used were medication refill requests (68%) and secure messaging (55%). After adjustment, each additional log-in per month was associated with a 0.12-point increase in adherence (p=0.003). Secure messaging use was associated with higher adherence (β=0.34, p=0.02). Qualitative themes included convenience, reminders, and improved communication, but also technical challenges and privacy concerns. Conclusions: Patient portal use is positively associated with medication adherence among older adults. Interventions to enhance portal usability and digital literacy may further improve outcomes.