P163 Emergency department opt-out testing for hepatitis B: a 2-year multicentre study of outcomes across 7 sites

<h3>Background and Aims</h3> Opt-out testing for blood-borne viruses (BBV) in emergency departments (ED) is now being rolled out across England, after a London-based pilot. Single-centre reports have identified large numbers of hepatitis B virus (HBV) infected patients who are not in care. Patient and disease characteristics and rates of engagement have not been studied across a large representative cohort. <h3>Methods</h3> We undertook a multicentre retrospective study of positive HBsAg patients across 7 ED testing hospitals from North and South London between April 2022 and April 2024. Recruitment was for a minimum of 12 months with a 6-month follow-up period. Patient and disease characteristics were compared with those referred by standard routes (e.g. primary, secondary and antenatal care – ‘non-ED’). <h3>Results</h3> A total of 339,627 HBsAg tests were performed, representing 29% of tests in the program in this period. A total of 983 HBsAg+ve patients were identified after exclusion of 167 equivocal/false positives. 96 patients were not contactable by phone or post. Of the 887 contacted, 209 were already under follow-up and 678 were not under care. Of these, 534 were new to service and 144 were lost to follow-up. 660/678 (97.3%) were successfully engaged for clinical assessment. In the ED cohort, 16.3% had a LSM &gt;7.0Kpa, 13.8% had a CAP score &gt;300 and 20.3% had a viral load &gt;2000. 14.2% were commenced on nucleotide therapy. 3 new cases of HCC and 4 new cases of HDV infection were identified. A Cox regression multivariate analysis of time from notification to assessment was performed. Covariates included age, gender, alcohol use, UK born, English-speaking status, aware of diagnosis and diagnosis in a hospital with a dedicated viral hepatitis service. Only the latter significantly improved time to assessment (HR 1.574, 95% CI 1.328 -1.865, p&lt;0.001). The ED cohort was significantly older (mean age μ=50.9 vs 47, p&lt;0.001), had a lower proportion of patients with HBV DNA &gt;2000 (20.3% vs 30.9%, p&lt;0.001) and higher CAP scores (μ=245 vs 236.9, p=0.042). ED testing resulted in an 109% increase in HBV assessments in the study period. <h3>Conclusions</h3> ED testing is more than doubling patient numbers entering hepatitis B services. Excellent rates of engagement can be achieved, delays are attributable to service differences rather than patient factors. A significant proportion would benefit from HCC surveillance and/or viral suppression. Further resources will be needed so that this rapidly expanding cohort benefits from longitudinal care without detriment to existing services.