Analysis of HIV/HCV Co-infection and Mortality across Cohorts of HIV+ Patients in Middle Tennessee

Background:  HIV/HCV co-infection is associated with poor health outcomes. This study was designed to determine the influence of HIV/HCV co-infection on mortality in a comprehensive cohort of HIV+ patients in Middle TN from 2004-2014.

Methods:  This retrospective cohort study analyzed electronic data from two large clinics comprising >90% of HIV+ persons in care in Middle TN: Meharry Community Wellness Center (MCWC) and Vanderbilt Comprehensive Care Clinic (VCCC). A third group included those with ≥1 visit at both clinics during the study period. In a Cox proportional hazards model controlling for cohort by stratification, HCV status, age, gender, race/ethnicity, HIV risk factors, most recent CD4 cell count and plasma HIV viral load were utilized to assess mortality.

Results: A total of 3624 patients were included: 24% female; median (IQR) age at first visit 39 (30-46); 50% MSM; 46% White/Caucasians; 45% African-Americans; median (IQR) most recent CD4 count was 500 cells/μL (298-714), and median (IQR) most recent HIV viral load 47 copies/mL (39-711). Prevalence of HCV was 13%. Total deaths were 309 and median (IQR) age at death 47 years (40-54). A total of 168 patients had visits at both clinics. Prevalence of IDU in this cohort (20%) was higher than at MCWC (14%) or VCCC (6%). In a multivariate Cox model, mortality increased with age (p=0.005). As expected, higher CD4 count and lower HIV viral load were associated with decreased mortality (p<0.001 for both), with independent protective associations noted with last CD4>500 cells/μL (HR 0.65; 0.59-0.71 vs. CD4 200-350) or viral load ≤2 log copies/mL (HR 0.54; 0.46-0.64 vs. 3-4 log). Race/ethnicity and IDU were only marginally associated with mortality (p=0.05 for both). When cohort was corrected for by stratification, HCV co-infection was associated with greater mortality (HR 1.72; 1.27-2.33; p<0.001).Conclusion:  HIV/HCV co-infection was an independent predictor of mortality across three diverse cohorts of patients. Future analyses will explore measures of the continuum of care and other health outcomes in this unique and highly representative population.