The Lancet Medical Imaging & Theranostics · Oct 2026
Association between multimorbidity, disease accumulation, multimorbidity clusters, and medical-imaging use and costs: a longitudinal study
By Arponen O, Vetrano DL, Calderón‐Larrañaga A et al.
Background Approximately a third of the global population is affected by multimorbidity, defined as having two or more chronic diseases, which increases health-care utilisation. However, the association of multimorbidity with medical-imaging use and related costs remains unknown. We aimed to investigate whether multimorbidity, faster accumulation of chronic diseases, or specific multimorbidity clusters are associated with increased use and costs of medical-imaging services. Methods This longitudinal study included participants from the Helsinki Birth Cohort Study who were assessed for multimorbidity at baseline between 2001 and 2004 and followed for medical-imaging use until Dec 31, 2019. Latent class analysis was used to identify multimorbidity clusters, and generalised linear models were used to assess whether baseline multimorbidity, chronic disease accumulation rate, and specific latent multimorbidity clusters are associated with medical-imaging service use and imaging-related costs. Findings Of the 1995 participants (mean age at baseline 61·5 years [SD 3·0]), approximately a third (751 [37·6%]) were affected by multimorbidity at baseline. Participants affected by multimorbidity underwent more than half of all imaging examinations (13 224 [52·5%] of 25 172) and had higher imaging use than those not affected by multimorbidity (incidence rate ratio [IRR] 2·09, 95% CI 1·82–2·36) and higher imaging costs over a median follow-up period of 16·9 years (IQR 16·2–17·7; Exp(β) 2·11, 95% CI 1·87–2·36). More rapid chronic disease accumulation over the follow-up period was associated with higher imaging service use and costs than was stable accumulation. Cluster analysis revealed four latent multimorbidity clusters—ie, cardiometabolic, musculoskeletal, respiratory, and unspecific. Participants in the cardiometabolic cluster had the highest imaging service use (IRR 3·44, 95% CI 2·39–4·50) and costs (Exp(β) 4·02, 95% CI 2·99–5·05) compared with those who were not affected by multimorbidity. Interpretation Multimorbidity, chronic disease accumulation, and cardiometabolic clustering of multimorbidity are associated with higher imaging service use and higher imaging costs in older adults. These findings suggest that planning imaging capacity should take into account multimorbidity burden and trajectories, and not population ageing trajectories alone. Funding None.