UC Irvine

Hepatitis C is the most infectious bloodborne disease in the United States. For my dissertation, I will focus on the study population in Orange County, California. This high-risk area has a significant substance use rehabilitation tourism industry with over 400 rehabilitation facilities).1 and a marked increase in reported HCV cases since 2011. 2 The purpose of this dissertation was to understand why, despite effective HCV treatment, Orange County patients who test antibody-positive are not directly followed up with viral load tests and then initiated on HCV treatment. This question merits further research using routinely collected and reported public health surveillance data and electronic medical records at health care facilities.

The goals of this research were to examine socioeconomic individual and group-level correlates of the following outcomes: HCV viral load testing, undetectable HCV viral load, and HCV diagnosis in a health care setting using the University of California, Irvine Medical Center (UCIMC) medical records with chart review. This research utilized secondary data using multivariable logistic regressions and multivariable Cox Proportional Hazard regression to answer these research questions.

With an n of 27,389 individuals, that only 3.16 percent of all patients from 2010 to 2020 showed undetectable viral load. Only 37 percent of these patients were not ever viral load tested from 2010 to 2020, leaving the viremic status of these patients unknown. Those over 65 were more likely to have an undetectable HCV viral load than younger adults (HR =2.00). Residents living in census tracts in the third and fourth quartiles of percent enrollment in health insurance showed a greater likelihood of undetectable viral load. When examining 521 electronic medical records (EMRs), only 22 percent of those reported as HCV antibody-positive indicated an HCV-positive diagnosis in their EMR. Less than one percent of patients n=5 were prescribed HCV treatment. These results show an alarming loss of follow-up and an inability to link patients to care with an opportunity to improve outcomes. The findings of this study are essential for informing future HCV policies and diagnosis procedures to get individuals tested and treated for this disease.