O8 Epidemiology of liver disease and associated patient characteristics in Wales 2004–2022: a retrospective population-scale observational study

<h3>Introduction</h3> Understanding the clinical and demographic characteristics of individuals with liver disease is crucial for clinical services including disease prevention, early detection, and targeted intervention. To date, lack of integration of data from primary and secondary care and death records has limited longitudinal characterisation of individuals with liver disease. In this study, we describe the incidence and key characteristics of individuals with liver disease in Wales using a combination of anonymised individual-level, linkable population-scale primary, secondary, and mortality data. <h3>Method</h3> In this population-scale observational study, individuals diagnosed with liver disease during our study period (01/01/2004 to 31/12/2022) were identified using the Secure Anonymised Information Linkage (SAIL) Databank, which incorporates Welsh Longitudinal General Practice (WLGP) primary care data, Patient Episode Database for Wales (PEDW) secondary care data, and Annual District Death Extract (ADDE) from the Office for National Statistics (ONS) mortality data. The incidence of liver disease, underlying aetiology, and comorbidities were described. Annual age-standardised incidence rates per 100,000 inhabitants were reported based on data sources, disease stages and aetiologies. <h3>Results</h3> Between 2004 and 2022, 111,098 individuals received a diagnosis of liver disease in Wales and were included in this study. The incidence of liver disease increased three-fold during the study period (2004: 97.7 per 100,000 inhabitants; 2022: 316.2 per 100,000 inhabitants). A total of 79,992 individuals (72%) entered the cohort with the aetiologies of liver disease, including alcohol related liver disease (ArLD), non-alcoholic fatty liver disease (NAFLD), viral hepatitis, metabolic, hemochromatosis and autoimmune liver diseases. NAFLD has contributed to most of the increase in incidence, with an eleven-fold increase during study period (2004: 10.8 per 100,000 inhabitants; 2022: 120.4 per 100,000 inhabitants). We observed a high proportion of individuals with comorbidities such as hypertension (24,852 [23.7%]), diabetes (3,811[3.6%]), and CVD related conditions (4,998[4.8%]) over 10 years prior to their first liver disease diagnosis. Furthermore, we noticed an increasing number of incident cases were identified from the primary care data during the past decades (14% in 2004, 28% in 2022). <h3>Conclusion</h3> We observed increasing incidence rates of liver disease in Wales, with NAFLD showing a particularly sharp increase and frequently identified as an underlying condition. The increasing number of primary care cases indicated possible impact of policy interventions that implemented pathways to facilitate early detection in Wales. It is therefore crucial to focus more attention on early detection, lifestyle interventions, and comprehensive management of both liver disease and its associated comorbidities.