# Trends in Utilization and Costs Following a Hepatitis C Elimination Initiative

## TL;DR

Washington State's hepatitis C elimination initiative led to increased screening and treatment, and eventually reduced care costs over time.

## Contribution

Demonstrated that expanded HCV screening and treatment access can reduce long-term care costs.

## Key findings

- HCV screening increased significantly after the initiative's implementation in 2019.
- The proportion of newly diagnosed cases receiving treatment rose from 16.8% in 2017 to 24.9% in 2021.
- Total care costs decreased by $520 per month per case by 2021 compared to 2019.

## Abstract

What are the trends in hepatitis C virus (HCV) screening, diagnosis, treatment, and cost before and following implementation of a statewide HCV elimination initiative?

This case series analysis of state claims data for more than 21 million unique individuals found that the number of HCV tests per month in Washington increased substantially 1 year after implementation, with prevalence increasing from 2017 to 2021 before declining significantly during 2022. Total costs for care increased from 2017 through 2019, consistent with higher prevalence during this period, but declined after mid-2020, even when prevalence was increasing.

These findings suggest that expanded screening and access to treatment may decrease costs of HCV care over time.

This case series examines trends in hepatitis C virus screening, prevalence, treatment, and costs before and after Washington State’s hepatitis C virus elimination initiative.

Expanded screening and treatment options as part of national guidelines and statewide policy initiatives have the potential to eliminate hepatitis C virus (HCV).

To describe trends in HCV screening, prevalence, treatment, and costs before and after Washington State’s HCV elimination initiative.

This case series is an observational analysis of retrospective claims data aggregated at the individual-month level. The dataset included individuals in the Washington State All Payers Claims Database between January 2017 and September 2022. Analyses were conducted from August to November 2025.

In July 2019, as part of a directive from the governor, the Washington State Department of Health released a comprehensive HCV elimination strategy. The plan included discounted and subscription-based payment models and removal of restrictive prior authorization and specialist consultation requirements.

International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) and Current Procedural Terminology codes were used to identify HCV testing or screening, ICD-10 diagnosis codes were used for HCV infections, and the National Drug Codes were used for HCV direct-acting antiviral medications. An individual was considered to have newly diagnosed HCV at the earliest month in which they had an HCV test claim followed by 2 HCV diagnosis codes within the subsequent 12 months and no HCV diagnosis during the 6 months before the test month. Total health care costs per month were computed, excluding cost of HCV direct-acting antiviral medications. Interrupted time-series approaches computed trends over time using the second quarter (Q2) of 2019 as a reference time point.

More than 21 million unique individuals (mean [SD] age, 44 [26] years; 11 085 080 female [53%]) were included in the data extraction. The number of HCV tests per month was stable during the preinitiative and immediate postinitiative period. Beginning in 2020 Q3, screening increased significantly from the reference quarter by 10.5 additional tests per month per 1000 Washington enrollees (95% CI, 8.8 to 12.2 tests per month per 1000 enrollees; P < .001). Consistent with increased screening, the prevalence of chronic HCV cases increased through 2021, but declined by 0.4 cases per 1000 enrollees comparing 2019 Q2 to 2022 Q3 (95% CI, −0.6 to −0.2 cases per 1000 enrollees; P < .001). The proportion of newly diagnosed cases receiving any HCV treatment increased from 16.8% (634 of 3776 cases) in 2017 to 24.9% (472 of 1894 cases) in early 2021 (difference, 8.1 percentage points; 95% CI, 5.8 to 10.4 percentage points; P < .001), but slopes before and after 2019 Q2 were not significantly different. Costs per ever prevalent case decreased significantly by 2021 Q1 (−$520 per month compared with 2019 Q2; 95% CI, −$922 to −$124 per month; P = .01).

In this longitudinal case series analysis of claims data, Washington State’s elimination initiative, combined with revised national screening guidelines and improved treatment options, contributed to expansion of HCV screening and changes over time in the proportion of people identified and treated for HCV, as well as decreased overall care costs.