Multimorbidity Patterns, Hospital Uses and Mortality by Race and Ethnicity Among Oldest-Old Patients

Adults aged 85 years and older ("oldest-old") are perceived as survivors resilient to age-related risk factors. Although considerable heterogeneity has been often observed in this population, less is known about the unmet needs in health and healthcare service utilization for diverse patients in healthcare systems. We examined racial-ethnic variation in patterns of multimorbidity associated with emergency department (ED), clinic visits, and mortality among the oldest-old patients with multimorbidity.

Administrative and clinical data from an integrated healthcare system for five years included 25,801 oldest-old patients with two or more chronic conditions. Hierarchical cluster analysis identified patterns of multimorbidity by four racial-ethnic groups (White, Black, Hispanic, & Other). Clusters associated with ED and clinic visits, and mortality were analyzed using generalized estimation equations and proportional hazards survival model, respectively.

Hypothyroidism, Alzheimer's disease and related dementia, bone & joint conditions, metabolism syndrome, and pulmonary-vascular clusters were commonly observed across the groups. While most clusters were significantly associated with ED and clinic visits among White patients, bone & joint conditions cluster was the most significantly associated with ED and clinic visits among Black (RR = 1.32, p <.01 for ED; RR = 1.67, p <.0001 for clinic) and Hispanic patients (RR = 1.36, p <.0001 for ED; RR = 1.39, p <.0001 for clinic). Similar patterns were observed in the relationship between multimorbidity clusters and mortality.

Patterns of multimorbidity and its significant association with the uses of ambulatory and emergency care varied by race-ethnicity. More studies are needed to explore barriers when minoritized patients are faced with the use of hospital services.