Effects of GPS Tracking on Patient Adherence to Hepatitis C Treatment Among People Experiencing Unsheltered Homelessness

Previous research on Hepatitis C infection (HCV) has found positivity rates between 12% and 27% among people experiencing homelessness; far exceeding typical rates found among a general housed population (1%). The usual course of HCV care in the healthcare system is screening and diagnosis in primary care, then referral to specialty care (such as Hepatology or Gastroenterology) for treatment. All of this takes place within the confines of traditional "brick and mortar" clinics. This screen, refer, and treat model presents a multitude of person- and systems-level barriers for individuals experiencing homelessness.

Street Medicine was developed as an alternative healthcare delivery model to better account for the unique circumstances of the unsheltered homeless population and better meet their healthcare needs. It is defined as the delivery of individually tailored health and social services to people experiencing unsheltered homelessness directly in their own environment. Street Medicine clinicians are ideally positioned to screen, diagnose, and treat patients for HCV. Treatment of uncomplicated HCV requires daily medication for 8 to 12 weeks. Our pilot data show that USC Street Medicine can successfully engage patients in HCV treatment on the street (93% successful follow-up rate), however, adequate longitudinal follow-up for effective treatment has been a problem for other programs.

Innovative, practical, and ethical solutions to help locate patients experiencing homelessness who require follow-up for medical treatment are needed. One such potential solution is the use of discreet GPS tracking devices that may be activated when providers are in the field to locate and provide care to patients. GPS tracking devices have been used by other Street Medicine programs caring for patients experiencing homelessness. However, no research has used GPS devices for the treatment of HCV amongst people experiencing unsheltered homelessness or formally elicited the patient perspective.

This study seeks to evaluate the impact of using a GPS tracker among patients engaged in street-based treatment for HCV on medication adherence. This is a multi-site randomized controlled study to test the impact of using a GPS tracker vs. usual care (no tracker) on HCV medication adherence, along with individual interviews to explore the perspective of unsheltered homeless patients engaged in both study arms.

In this study, the use of the GPS tracker constitutes the experimental research; not the treatment for HCV. Initial screening for HCV will have already occurred as part of usual street medicine healthcare prior to this study and will not be conducted as part of this research.