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) ( = 43 568) for no cirrhosis, $661 (95% CI $630-$692) ( = 6422) for no cirrhosis (RNA negative), $1487 (95% CI $1375-$1599) ( = 4970) for compensated cirrhosis, $3659 (95% CI $3279-$4039) ( = 3151) for decompensated cirrhosis, $4238 (95% CI $3480-$4996) ( = 550) for hepatocellular carcinoma, $8753 (95% CI $7130-$10 377) ( = 485) for both decompensated cirrhosis and hepatocellular carcinoma, $4539 (95% CI $3746-$5333) ( = 372) for liver transplantation, $11 202 (95% CI $10 645-$11 760) ( = 3201) for terminal (liver-related) and $8801 (95% CI $8331-$9271) ( = 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.