Association of Secure Messaging with Primary Care In-Person and Telephone Visits Among Veterans: a Matched Difference-in-Difference Analysis

BACKGROUND Secure messaging (SM) between patients and primary care teams has expanded care access but may impact other clinical encounters. OBJECTIVE To study associations between SM use and primary care in-person and telephone visits in the Veterans Health Administration (VHA). DESIGN The SM feature of VHA's patient portal, MyHealtheVet, supports asynchronous communication between patients and primary care teams. To study the impact of SM on in-person and telephone visits, two analyses were performed: (1) a retrospective pre-/post-analysis comparing changes after initiating SM use and (2) a difference-in-difference comparison among SM users and non-users 1 year before and after index SM use. Matching to non-users was by primary care team, demographics, and predicted propensity of SM use by Nosos comorbidity score and drive time to clinic. PATIENTS In 2016, 154,053 Veterans initiated SM from all primary care patients (N = 5,891,893); 25,683 were propensity-matched to controls (N = 49,266) from the same primary care team not using SM. MAIN MEASURES Primary care provider in-person visits and telephone contacts between patients and their primary care team were assessed 1 year prior and post index SM. KEY RESULTS Overall, primary care in-person visits decreased 13.3% (p < 0.0001); telephone visits increased 13.5% (p < 0.0001). In the matched analysis, in-person primary care visits decreased by 16.0% (p < 0.0001) by SM users and 9.9% (p < 0.0001) among controls, resulting in a across-group decrease of 6.1% in-person visits after SM initiation. Telephone visits increased by 11.0% (p < 0.0001) for SM users and 4.5% for controls (p < 0.0001) resulting in an across-group increase of 6.5% telephone visits after SM initiation. CONCLUSIONS Use of SM was associated with decreased in-person visits and increased telephone visits. This may improve clinic appointment availability, while increasing time commitments for providers for non-traditional forms of access.