Project Summary/Abstract
People who inject drugs (PWID) account for the majority of hepatitis C virus (HCV) infections in the U.S.
Improving the HCV care continuum, with particular attention to the complication of HIV-coinfection, is critical
to achieving HCV elimination. Heterogeneous injection and sexual networks among PWID can significantly
affect HCV and HIV transmission and intervention outcomes. Although empirical studies on the efficacy of
interventions to improve the HCV care continuum in the direct-acting antiviral (DAA) era have begun to
accumulate, there remains a lack of understanding of the population level impact and cost-effectiveness of
these interventions to inform policymaking. My long-term goal is to develop mathematical and statistical
simulation models to inform health policies relating to infectious disease control. The overall objective for
this application, which is a critical step toward attaining my long-term goal, is to develop a dynamic agent-
based network model of HCV and HIV transmission among PWID, to determine the population-level impact
and cost-effectiveness of interventions to improve the HCV care continuum. My central hypothesis is that
interventions that target multiple stages of the care continuum, taking account of individual characteristics,
service environment, and meso/macro-level contexts, will have significant population-level impact in
decreasing HCV and HIV infections and associated complications while being cost-effective. The central
hypothesis will be tested by pursuing three specific aims: 1) Identify social determinants of the HCV care
continuum outcomes among PWID, and effective interventions to improve these outcomes in the DAA era;
2) Determine the population-level impact and cost-effectiveness of different interventions to improve the
HCV care continuum among PWID; 3) Identify the determinants of differences in population-level impact of
interventions to improve the HCV care continuum based on specific features of PWID networks. I will
pursue these aims using systematic review and meta-analysis (Aim 1), expanding our model of HCV
transmission via injection network to incorporate sexual network and HIV transmission (Aim 2), and fitting
the model to different PWID networks and evaluate impact across the networks (Aim 3). To complete the
research and advance my career, I will obtain research training in evidence synthesis, Bayesian methods
for model calibration, and health economics, and professional training in scientific communication,
leadership, and collaboration, in the interdisciplinary environment of the Department of Health Policy at the
Stanford School of Medicine. The expected outcome is a novel model platform to evaluate complex
HIV/HCV intervention strategies for improving the health of PWID. The proposed research is significant
because the results will provide systematic understanding of social determinants of HCV care in PWID and
essential evidence on the population-level impact and cost-effectiveness of interventions to improve the
HCV care continuum in different PWID populations to inform policymaking on HCV elimination.