Clustering of Multimorbidity and Social Care Needs: 10-year all-cause mortality in a cohort study of more than 7 million people

BackgroundResearch on multimorbidity--commonly defined as the presence of two or more long-term conditions--has predominantly focused on biological and clinical needs. However, unmet social care needs (SCNs), including, for example, mobility limitations, financial hardship, and social isolation, can also adversely affect health outcomes. We aimed to identify distinct clusters of individuals with multimorbidity and SCNs, and to examine their associations with 10-year all-cause mortality. MethodsWe analysed data from the Clinical Practice Research Datalink (CPRD) Gold and Aurum databases (Jan 1, 1987, to Dec 31, 2020) to identify adults in England living with multimorbidity. Latent class analysis was used to derive clusters based on long-term conditions and eight predefined domains of SCNs. Threshold criteria were applied to determine meaningful representation of long-term conditions and SCNs within each cluster. Associations with 10-year all-cause mortality were assessed using Cox proportional hazards models, adjusted for age, sex, ethnicity, deprivation, multimorbidity burden, SCNs, and year of multimorbidity diagnosis. FindingsAmongst 7.2 million individuals with multimorbidity (mean age 54.4 years [SD 18.2]; 55% female), 37% had at least one SCN, with community care needs being the most common (28%). Four distinct clusters were identified: Cluster 1 (mean age 37.3 years [SD 14.5]) comprised individuals with predominantly mental and behavioural conditions, no SCNs, high deprivation, and the lowest mortality risk (reference group); Cluster 2 (mean age 57.9 years [SD 16.3]) included those with cardiovascular, musculoskeletal, and mental and behavioural conditions, no SCNs, and a higher mortality risk (adjusted hazard ratio [aHR] 1.47 [95% CI 1.45-1.48]);Cluster 3 (mean age 62.6 years [SD 16.4]) had similar clinical profiles to cluster 2 but the highest SCN burden, lower deprivation, and the greatest mortality risk (aHR 2.83 [2.75-2.92]); Cluster 4 (mean age 62.6 years [SD 15.2]) exhibited the highest burden of long-term conditions, two SCNs, high deprivation, and elevated mortality (aHR 1.49 [1.47- 1.51]). InterpretationWe identified four distinct clusters of individuals with varying profiles of multimorbidity, social care needs, and mortality risk. These findings underscore the importance of personalised, integrated care approaches and support the development of targeted interventions to address the complex and intersecting needs of the most vulnerable populations. Research in ContextO_ST_ABSEvidence before this studyC_ST_ABSPrevious research highlights worse health outcomes for those with multimorbidities and increased social care needs. We carried out a rapid scoping review, which highlighted a lack of clarity on the definition of social care needs in this population, with no consensus in the literature. This has limited the ability to conduct research that draws meaningful comparisons across studies. To address this, we conducted a Delphi study that identified eight domains of social care needs, which we subsequently validated through a cross-sectional study. We also conducted two additional cross-sectional studies using latent class analysis of the English Longitudinal Study of Ageing (ELSA) dataset, clustering by one social care need (activities of daily living), multimorbidities, and socio-demographics. Added value of this studyTo our knowledge, this is the first study to apply latent class analysis to the Clinical Practice Research Datalink (CPRD) to identify clusters based on eight domains of social care needs among individuals with multimorbidity. By examining associations with 10-year all-cause mortality, we identified four distinct clusters, highlighting variations in risk and care needs. Our findings suggest that older adults (aged [≥]65 years) and individuals living in the most socioeconomically deprived areas are at greatest risk. These insights offer a foundation for developing targeted, integrated care strategies tailored to the complex and overlapping social care needs and multimorbidity of vulnerable populations. Implications of all the available evidenceThe findings highlight the need for targeted policies that prioritise individuals aged 65 years and older with high social care needs and multimorbidity. Integrating primary and community care services, alongside expanding opportunities for social participation, may help address the complex needs of this group. In addition, tailored interventions for working- age adults--particularly those experiencing socioeconomic deprivation, from minoritised ethnic groups, or living with moderate multimorbidity but without significant social care needs--could slow health deterioration and reduce future social care demands. These insights support proactive, stratified approaches to care that respond to the intersecting challenges of multimorbidity and social care needs across the life course.