MCCs in adults with autoimmune and inflammatory rheumatic diseases: evidence to date and future directions

Multiple chronic conditions (MCCs), also known as multimorbidity, are highly prevalent in adults with autoimmune and inflammatory rheumatic diseases (AIIRDs) and significantly complicate their management. This narrative review summarizes current literature on the epidemiology of MCCs in various AIIRDs, highlighting their association with adverse health outcomes and proposing future directions for care. MCCs are ubiquitous across AIIRDs, often exceeding rates seen in age-matched general populations, with prevalence as high as 86% in rheumatoid arthritis and 81.5% in systemic lupus erythematosus cohorts and notable patterns including cardiopulmonary and mental health disorders frequently observed. This substantial MCC burden is consistently linked to adverse outcomes, including increased all-cause mortality, reduced functional status, diminished health-related quality of life, accelerated disability, higher healthcare utilization, and increased costs, driven by chronic inflammation, lifestyle, and treatment effects. Therefore, rheumatology care must adopt a holistic, person-centered framework that actively recognizes and manages MCCs, leveraging multidisciplinary teams and integrating evidence-based interventions guided by frameworks such as the geriatric 5Ms and 5Ts to advance the science of MCCs in adults with AIIRDs and improve outcomes and optimize health-related quality of life in this complex patient population.