Clusters of people with multiple long-term conditions across socioeconomic and ethnic groups and their association with unplanned hospitalisations: A population-based cohort study from England

Background: Multiple long-term conditions (MLTC) are highly prevalent and lead to poor health and increased healthcare utilisation. Evidence is needed to identify clusters of people with MLTC across socioeconomic and ethnic groups and examine their association with unplanned hospitalisation, to better understand differences in MLTC patterns and healthcare needs. Methods: We used data from Clinical Practice Research Datalink (CPRD) Gold linked to Hospital Episode Statistics (HES). We included patients aged 18 + years on 01/01/2018, with ≥ 2 long-term conditions (LTC), and with ≥ 1 year of data visibility. Conditions of interest were identified based on clinical knowledge and prevalence ≥ 5%. We applied latent class analysis (LCA) to identify clusters with similar MLTC patterns overall and stratified by area deprivation and ethnicity. We assessed the association between cluster membership and the risk of one-year unplanned hospital admission through Cox proportional hazards regression. Results: 237,156 (57.7% women) patients were included. LCA identified a total of five distinct MLTC clusters. Across all stratified analyses, we identified five distinct MLTC clusters. Four clusters were identified in the least deprived areas, while three were identified in the most deprived areas and three within each ethnic group. “High-MLTC” (characterised by patients with a high prevalence of most conditions) and “mental health” clusters were observed in all sub-groups. An “inflammatory” cluster (defined by high prevalence of inflammatory conditions) was observed only in the least deprived areas and White ethnicity, whereas a “cardiometabolic” cluster (with high prevalence of cardio-metabolic conditions) was observed solely in the most deprived areas and among Black and Asian ethnic groups. An “obesity” cluster, characterised by obesity with fewer other conditions, was observed only among those residing in the least deprived areas.