Impact of a community liver pathway on referrals to secondary care liver services: a natural experiment using controlled interrupted time-series analysis

Objective To evaluate the impact of the Southampton Liver Pathway (SLP), a community-based liver disease detection programme, on hospital hepatology referrals. Method The SLP was implemented in Southampton City Clinical Commissioning Groups (SCCG) in January 2018. At-risk patients underwent enhanced liver fibrosis testing, with those scoring >9 referred for community-based FibroScan. Patients with liver stiffness >10 kPa were recommended for secondary care referral. A controlled interrupted time-series (CITS) design was used to compare monthly hepatology referral rates in SCCG before and after implementation with those in a control region (West Hampshire Clinical Commissioning Group, WHCCG) where no pathway existed. Potential system-level confounders were assessed by analysing trends in non-hepatology referrals and fibrosis testing volumes. Results Following implementation, 1654 new hepatology referrals were made from SCCG over 19 months (median 37/month, range 25–57), compared with 44/month pre-SLP (range 30–64). In WHCCG, referrals remained stable (median 28/month, range 20–41 pre-SLP, 14–34 post-SLP). CITS analysis showed a significant reduction in hepatology referrals in SCCG after the SLP was introduced compared with both the control region (incidence rate ratio, IRR 0.95, 95% CI 0.93 to 0.98, p=0.001) and the preimplementation period (IRR 0.97, 95% CI 0.95 to 0.98, p<0.001). This reduction was not explained by system-level confounders: non-hepatology referrals increased and primary care fibrosis testing rose postimplementation. Conclusions The introduction of a structured primary care liver disease pathway was associated with a significant reduction in secondary care hepatology referrals. These findings suggest that such community-based pathways may alleviate hospital pressures, even as liver disease detection activity increases.