A scoping review on multimorbidity clustering and its effect on treatment burden and the utilisation of health and social care services in the United Kingdom

Problem

Multimorbidity has been linked to high rates of GP use, unplanned hospital admissions, emergency visits, medication use and healthcare costs. Little is known regarding the uptake of social care. There is limited evidence on how long-term chronic conditions (LTCs) accrue, interrelate and cluster, and associated risk factors. The scoping review aimed to collate and map existing evidence (key factors, definitions, concepts, and evidence gaps) on multimorbidity clustering, treatment burden and the utilisation of health and social care services.

Approach

The Joanna Briggs Institute (JBI) approach and the Arksey and O’Malley framework methodologically guided the scoping review. An online search was conducted in 2022 and updated in 2023 to identify published studies (1970-2023) in PubMed, Cochrane Library, CINAHL, Medline and Social Care Online databases. Key concept terms were multimorbidity, clusters, health service use, social care use, treatment burden. Two reviewers conducted the article screening, quality assessment and analysis.

Findings

Search results identified 2254 database studies and 31 studies from other sources. Title and abstract screening excluded 1339 studies due to a lack of focus on multimorbidity (1150), non-UK based studies (184), and studies with a wrong population group (5). Fifty-one studies, majority of which were conducted in England and majorly within primary care settings, were included. Multimorbidity clusters ranged from 3 to 20 with diabetes, hypertension, and asthma as the most central LTCs. The main clusters were “cardiovascular,” “mental health,” “dependency,” “musculoskeletal” and “pain-related.” Depression (young demographic) and diabetes and chronic heart disease (CHD) (old demographic) were the first LTCs in the order of acquisition. In the most deprived areas, depression commenced the acquisition order while diabetes and CHD were the first LTCs in the acquisition order in the least deprived areas. Cluster transitions were prompted by ageing and the level of deprivation. The highest rates of consultation, hospital admission and prescription use were found in clusters with depression, anxiety and pain (18-44 years), clusters with pain, psychoactive substance misuse and alcohol use (45–64 years), clusters with hypertension, hearing loss, depression, CHD, and pain (65–84 years), and clusters with CHD, pain, atrial fibrillation and heart failure (>85 years).Treatment burden was associated with young age, being female, high number of primary care appointments, multiple medication use, and having more than 4 LTCs.

Consequences

The evidence on the timing and the acquisition order of LTCs is crucial when tailoring treatment programs that target different disease combinations at their stage of accrual. Studying the trajectories of clusters over time offers a unique perspective on the entry points of LTCs within the multimorbidity cascade. This is key to organising multimorbidity care for the at-most risk patient groups and when identifying principal domains of treatment burden.