Identifying Patient Portal Messages from Care Partners of People with Dementia.

Background: Patient portals provide a centralized platform for accessing health information and communicating with healthcare providers, offering benefits for care partners of people with dementia. However, uptake of shared proxy access remains limited, with many care partners informally using patient credentials. This study aimed to identify portal messages sent from care partners of people with dementia and describe associated portal use. Methods: A retrospective cohort study was conducted at Kaiser Permanente Colorado involving N=521 people with dementia ≥60 years. Data extracted from electronic health records included standardized contact information and unstructured portal messages. Names of potential care partners, termed here "known contacts", were identified through structured fields (emergency contacts, patient contacts, healthcare proxies). A rules-based approach was developed to identify messages from known contacts and validated through manual review. Messages were linked to portal activities performed the same day to describe patterns of use. Results: Among the cohort (N=521), 402 (77%) people with dementia had messages sent on their behalf from a known contact, predominantly children and spouses. Known contacts sent a mean of 13.7 messages. Of all threads, 7% were from proxy accounts; 53% of messages did not identify a known contact, and 40% did. 67% of the cohort had portal activity on the same day as a known contact message. Known contacts more often accessed "Visits and appointments" and less often "Medications" after sending messages. Conclusion: Known contacts may use patients' portal accounts for broader care management beyond messaging. Identifying known contact portal use could ultimately help health systems to recognize care partners, provide timely support, improve portal privacy and accuracy, and facilitate formal proxy registration.