High Users of Primary Care Secure Messaging in the Veterans Health Administration.

Purpose: Secure messaging has increased in primary care, but we lack information on who uses it at a high level. Characterizing this population is important to inform policy about patients most likely to be affected by secure messaging reimbursement and coverage decisions; to contextualize the secure messaging work burden for primary care; and to understand how secure messaging complements use of other primary care access points. Our objectives were to describe characteristics of high users, assess their overall primary care and emergency department use, and determine the proportion of total Veterans Health Administration primary care messages exchanged by this group.

Methods: We conducted a 1-year retrospective cross-sectional analysis and multivariate logistic regression analysis of all veterans assigned to primary care on October 1, 2022 who exchanged at least 1 secure message with primary care by September 30, 2023. We calculated descriptive statistics and assessed whether certain veteran characteristics were associated with high user status (use in the 95th or higher percentile of all messages exchanged annually).

Results: Patients were more likely to be high users if they were older (adjusted odds ratio [aOR] for age ≥75 years = 2.49); had highest frailty (fourth quartile aOR = 2.65) or high physical comorbidity (Gagne score of 2 aOR = 1.17 and score of 3 aOR = 1.14); lived with schizophrenia or bipolar disorder (aOR = 1.23); or had posttraumatic stress disorder, anxiety, or depression (aOR = 1.16) ( < .05 for each). Patients were less likely to be high users if they identified as Black (aOR = 0.74), Hispanic (aOR = 0.80), or Asian/Pacific Islander/Native Hawaiian (aOR = 0.85), or were male (aOR = 0.78) ( < .05 for each). High users exchanged 30.5% of all messages. Few high users of secure messaging were also high users of other primary care encounters (only 14.0% were high users of in-person visits, 11.3% of video visits, and 11.8% of telephone visits) or the emergency department (8.0% of visits).

Conclusions: A small percentage of veterans exchange a disproportionate share of total secure messages. Most high users of secure messaging do not use other primary care or emergency department services at the same high frequency as secure messaging. High users commonly have high physical comorbidity, are frail, and live with mental health conditions, and racial disparities exist.