Given the disproportionately high risk of chronic hepatitis C virus (HCV) infection in the baby boomer cohort, population-based screening has been demonstrated cost effective. Compared to point-of-care testing, however, bulk health messages with coupled lab requisitions delivered directly to patients meeting screening criteria via patient portals could improve HCV screening at minimal cost.

The Centers for Disease Control and Prevention (CDC) and the United States Preventative Services Taskforce (USPSTF) recommend a one-time hepatitis C infection (HCV) screen in individuals born 1945-65 (baby boomer birth cohort) and in others with risk factors for infection. National adherence to this Grade B recommendation-carrying the same strength of evidence as mammography, and screening for depression, alcohol abuse, and type 2 diabetes-is estimated to be 13.8%. Efforts to increase screening and linkage to HCV care, and also to understand barriers to screening and linkage are therefore warranted.

One such intervention, direct-to-patient messages via electronic medical record (EMR), has been demonstrated to improve adherence in influenza and pneumococcal vaccination, colon cancer screening, immunosuppression after transplantation, among others, but has not been studied as a strategy to improve HCV screening rates within health systems.

Our institution, Stanford Health Care, comprises 86 distinct clinical sites with approximately 1.25 million outpatient visits per year. All clinical sites are linked with an EMR (Epic Systems Corp.) and patients are encouraged to opt-in to receive and send health-related messages through a secure internet and smartphone portal, MyHealth. Approximately 60% of patients at our institution are enrolled in MyHealth.

MyHealth additionally allows bulk-messaging of patients meeting specific characteristics, e.g. patients due for influenza vaccination. Bulk messages can be coupled with laboratory or radiology requisitions. Messages are delivered through the online portal, text message, e-mail, and/or smartphone application notification, depending on patient preference. Laboratory and radiology results are routed automatically to patients' primary care physicians for review.

The investigators propose to conduct a randomized study comparing the effectiveness of a direct-to-patient electronic health message on HCV screening coupled with a lab requisition, versus HCV screening initiated by primary care clinicians as part of routine clinical care alone.

Inclusion Criteria:

• persons born between 1945-1965
• having an activated patient portal to receive secure messages (MyHealth)
• no prior HCV antibody test within our EHR (electronic health record), including externally accessible results

Exclusion Criteria:

• documented HCV viral load in our EHR
• diagnosis of chronic HCV in their problem list

Data will not be shared.