Impact of COVID-19 Pandemic on Testing for Hepatitis B in British Columbia, Canada: An Interrupted Time Series Analysis

Abstract Background Previous research suggests the COVID-19 pandemic was associated with reductions in HBV testing early in the pandemic. However, impacts of the pandemic on HBV testing in the longer-term and among people who inject drugs (PWID) are unclear. We investigated the impact of the pandemic and related policies on HBV testing from 2020 to 2022, including among PWID, in British Columbia (BC), Canada. Methods Using population data from the BC COVID-19 Cohort, we conducted interrupted time series analyses of HBV surface antigen (HBsAg), HBV DNA, and HBV e-antigen (HBeAg) testing. The study included a prepandemic period (January 2017–February 2020), a transition period (March–May 2020), and pandemic periods in 2020 (June–December), 2021, and 2022. Results HBsAg testing decreased by 16.5% (95% CI 13.9–18.9) and HBV DNA testing decreased by 11.6% (95% CI 9.5–13.6) in June–December 2020 relative to predicted levels, and testing remained lower than predicted throughout 2021 and 2022. Percentage reductions in HBV DNA testing were greater for PWID compared with non-PWID in 2020 (30.0% vs 11.2%) and thereafter. Changes in HBeAg testing overall were less pronounced but varied by sex and age. Conclusions The pandemic and related policies were associated with decreases in HBsAg and HBV DNA testing in 2020, and testing remained lower than predicted throughout 2021 and 2022. Additional efforts to increase HBV testing are needed, including strategies to ensure linkage to care for PWID.