Association of Complex Multimorbidity and Long-term Survival After Emergency General Surgery in Older Patients With Medicare

Abstract

Although nearly 1 million older patients are admitted for emergency general surgery (EGS) conditions yearly, long-term survival after these acute diseases is not well characterized. Many older patients with EGS conditions have preexisting complex multimorbidity defined as the co-occurrence of at least 2 of 3 key domains: chronic conditions, functional limitations, and geriatric syndromes. The hypothesis was that specific multimorbidity domain combinations are associated with differential long-term mortality after patient admission with EGS conditions. To examine multimorbidity domain combinations associated with increased long-term mortality after patient admission with EGS conditions. This cohort study included community-dwelling participants aged 65 years and older from the Medicare Current Beneficiary Survey with linked Medicare data (January 1992 through December 2013) and admissions for diagnoses consistent with EGS conditions. Surveys on health and function from the year before EGS conditions were used to extract the 3 domains: chronic conditions, functional limitations, and geriatric syndromes. The number of domains present were summed to calculate a categorical rank: no multimorbidity (0 or 1), multimorbidity 2 (2 of the 3 domains present), and multimorbidity 3 (all 3 domains present). Whether operative treatment was provided during the admission was also identified. Data were cleaned and analyzed between January 16, 2020, and April 29, 2021. Mutually exclusive multimorbidity domain combinations (functional limitations and geriatric syndromes; functional limitations and chronic conditions; chronic conditions and geriatric syndromes; or functional limitations, geriatric syndromes, and chronic conditions). Time to death (up to 3 years from EGS conditions admission) in patients with multimorbidity combinations was analyzed using a Cox proportional hazards model and compared with those without multimorbidity; hazard ratios (HRs) and 95% CIs are presented. Models were adjusted for age, sex, and operative treatment. Of 1960 patients (median [IQR] age, 79 [73-85] years; 1166 [59.5%] women), 383 (19.5%) had no multimorbidity, 829 (42.3%) had 2 multimorbidity domains, and 748 (38.2%) had all 3 domains present. A total of 376 (19.2%) were known to have died in the follow-up period, with a median (IQR) follow-up of 377 (138-621) days. Patients with chronic conditions and geriatric syndromes had a mortality risk similar to those without multimorbidity. However, all domain combinations with functional limitations were associated with significantly increased risk of death: functional limitations and chronic conditions (HR, 1.83; 95% CI, 1.03-3.23); functional limitations and geriatric syndromes (HR, 2.91; 95% CI, 1.37-6.18); and functional limitations, geriatric syndromes, and chronic conditions (HR, 2.08; 95% CI, 1.49-2.89). Findings of this study suggest that a patient's baseline complex multimorbidity level efficiently identifies risk stratification groups for long-term survival. Functional limitations are rarely considered in risk stratification paradigms for older patients with EGS conditions compared with chronic conditions and geriatric syndromes. However, functional limitations may be the most important risk factor for long-term survival.