Health care costs associated with chronic hepatitis C virus infection in Ontario, Canada: a retrospective cohort study

BACKGROUND: High-quality estimates of health care costs are required to understand the burden of illness and to inform economic models. We estimated the costs associated with hepatitis C virus (HCV) infection from the public payer perspective in Ontario, Canada. METHODS: In this population-based retrospective cohort study, we identified patients aged 18–105 years diagnosed with chronic HCV infection in Ontario from 2003 to 2014 using linked administrative data. We allocated the time from diagnosis until death or the end of follow-up (Dec. 31, 2016) to 9 mutually exclusive health states using validated algorithms: no cirrhosis, no cirrhosis (RNA negative) (i.e., cured HCV infection), compensated cirrhosis, decompensated cirrhosis, hepatocellular carcinoma, both decompensated cirrhosis and hepatocellular carcinoma, liver transplantation, terminal (liver-related) and terminal (non–liver-related). We estimated direct medical costs (in 2018 Canadian dollars) per 30 days per health state and used regression models to identify predictors of the costs. RESULTS: We identified 48 239 patients with chronic hepatitis C, of whom 30 763 (63.8%) were men and 35 891 (74.4%) were aged 30–59 years at diagnosis. The mean 30-day costs were $798 (95% confidence interval [CI] $780–$816) (n = 43 568) for no cirrhosis, $661 (95% CI $630–$692) (n = 6422) for no cirrhosis (RNA negative), $1487 (95% CI $1375–$1599) (n = 4970) for compensated cirrhosis, $3659 (95% CI $3279–$4039) (n = 3151) for decompensated cirrhosis, $4238 (95% CI $3480–$4996) (n = 550) for hepatocellular carcinoma, $8753 (95% CI $7130–$10 377) (n = 485) for both decompensated cirrhosis and hepatocellular carcinoma, $4539 (95% CI $3746–$5333) (n = 372) for liver transplantation, $11 202 (95% CI $10 645–$11 760) (n = 3201) for terminal (liver-related) and $8801 (95% CI $8331–$9271) (n = 5278) for terminal (non–liver-related) health states. Comorbidity was the most significant predictor of total costs for all health states. INTERPRETATION: Our findings suggest that the financial burden of HCV infection is substantially higher than previously estimated in Canada. Our comprehensive, up-to-date cost estimates for clinically defined health states of HCV infection should be useful for future economic evaluations related to this disorder.