Identification of the Risk Factors for Complex-Multiple Long-term Conditions (C-MLTC): A Scoping Review

BackgroundComplex multiple long-term conditions (C-MLTC) are commonly defined as the presence of four or more long-term conditions, and their prevalence is projected to increase significantly over the next decade. MethodsWe undertook a scoping review of the literature to identify available evidence on the risk factors for C-MLTC and map out the potential clusters. We focussed on a subset of 18 chronic conditions because they include the most commonly reported and prevalent conditions in the general population. For guidelines we searched NICE Clinical Knowledge Summaries (CKS) and for systematic reviews we searched PubMed, Google Scholar and the TRIP database. ResultsWe found 53 risk factors associated with 18 long-term conditions. Sixteen of these are linked to C-MLTC, with 11 being modifiable. Although we reviewed 51 systematic reviews, inconsistent reporting made it difficult to quantify the risk factors and conditions associated with C-MLTC. Diabetes mellitus was a risk factor for most other conditions (10), followed by coronary heart disease, hypertension, and chronic kidney disease (each associated with 8 long-term conditions). Additionally, depression and anxiety are commonly associated with other long-term conditions, with 19 and 20 conditions, respectively. ConclusionSeveral risks and conditions contribute to the development of multimorbidity. Anxiety and depression are nearly associated with all long-term conditions. Reporting problems within the existing evidence and a lack of clear definitions prevent adequate quantification of the risks related to C-MLTC.