{
  "abstract": "Background Multimorbidity, defined by the World Health Organization (WHO) as the coexistence of two or more chronic health conditions in an individual, is a growing public health concern. It is associated with a range of adverse patient outcomes, including reduced health-related quality of life (HRQoL) and higher mortality risk. While most multimorbidity research has focused on counts of conditions, there is increasing interest in the interactive and temporal effects of multimorbidity clusters on patient outcomes. The aim of this review was to systematically retrieve, synthesise and appraise the available evidence quantifying the association between multimorbidity clusters and patient outcomes.Methods A systematic search of Scopus (PubMed/MEDLINE), EMBASE, Web of Science, Ebsco APA PsyInfo and CINAHL was conducted from inception to February 2025. No language or time limits were applied. Original quantitative research quantifying patient outcomes according to multimorbidity clusters in adult populations ≥18 years were eligible for inclusion. The exposure of interest included chronic disease multimorbidity; that is, studies of patterns of co-occurring diseases without any single disease focus. Studies restricted to participants with a principal disease focus (e.g., a study population including only adults with diabetes (i.e., comorbidity studies)) and studies restricted to population health subgroups with specific health contexts (e.g., unhoused individuals, pregnant people) were excluded. Studies were required to have used data-driven methodology to classify diseases into multimorbidity clusters or combinations and to have included a minimum of 12 diseases into clustering analyses. Key outcomes of interest included mortality, HRQoL, mental health, patient-reported impacts and behaviours and physical activity and function.Results Our search retrieved 3415 articles, of which 42 were eligible for inclusion. Thirty-two studies were cohort design and 10 were cross-sectional. Study population sizes ranged from 411 to 6’286’233. Studies were based in middle- or high income countries, with the largest proportion of studies based in China (n=12), The UK (n=8) and Spain (n=4). Studies were heterogeneous in design, population and outcomes. The number of chronic conditions used for clustering analyses ranged from 12–112 conditions. Eight studies investigated the association between multimorbidity clusters and all-cause mortality, seven studies investigated the association between multimorbidity clusters and function, four studies investigated the association between multimorbidity clusters and HRQoL, four studies investigated the association between multimorbidity clusters and depressive symptoms, and the remaining 19 studies investigated a combination of the above outcomes.Conclusion This review is ongoing. Where sufficient homogeneity exists across studies in terms of population, multimorbidity clusters, and outcomes, a meta-analysis will be conducted. Findings will quantify the association between different multimorbidity clusters and patient outcomes which has potential to inform improvements in policy, practice and the delivery of health services in ageing populations with increasing prevalence of multimorbidity.",
  "authors": [
    {
      "affiliations": [
        "School of Public Health, University of Cork, Cork, Ireland"
      ],
      "name": "Joice Cunningham"
    },
    {
      "affiliations": [
        "School of Public Health, University of Cork, Cork, Ireland"
      ],
      "name": "Kate O’Neill"
    },
    {
      "affiliations": [
        "School of Public Health, University of Cork, Cork, Ireland"
      ],
      "name": "Prachi Sharma"
    },
    {
      "affiliations": [
        "School of Public Health, University of Cork, Cork, Ireland"
      ],
      "name": "Linda O’ Keefe"
    }
  ],
  "title": "P45 The association between multimorbidity clusters and patient-related outcomes: a systematic review",
  "uid": "f520eee7-5942-56e4-bd1a-17206e305e04"
}