The impact of primary care networks on emergency hospitalisations in the English NHS: an interrupted time series analysis

Recent years have seen an emergence of collaborative primary care models in the English National Health Service and other international health systems. Primary Care Networks (PCNs) were introduced in England in July 2019, marking the first time collaboration between general practices was incentivised through a nationwide policy. While participation was not mandatory, nearly all general practices joined a PCN, largely due to strong financial incentives. Our study aim was to estimate the impact of PCNs on emergency hospitalisations using an interrupted time series design. Quarterly data between October 2016 and March 2023 from the North West London Whole Systems Integrated Care dataset was used to construct two primary outcomes: all-cause and ambulatory care sensitive conditions (ACSC) emergency hospitalisations, as well as Accident and Emergency attendances, considered as a secondary outcome. Furthermore, we analysed whether the impact of PCNs varied based on practice characteristics. A reduction in all-cause and ACSC hospitalisations was observed following the PCNs’ introduction, until the start of the COVID-19 pandemic. The analysis also revealed a smaller reduction in ACSC hospitalisations among practices with more deprived patient populations and larger populations of patients with long-term conditions. While PCNs’ implementation appears to have led to a reduction in emergency hospitalisations in North West London, this effect was only observed in the very short term as it stopped with the COVID-19 pandemic. Future studies should examine the effect across England and evaluate their continued impact.