Cognitive impairment is associated with mortality in older adults in the emergency surgical setting: Findings from the Older Persons Surgical Outcomes Collaboration (OPSOC): A prospective cohort study

Abstract

Background: Cognitive impairment is prevalent in older surgical patients; however, the condition is greatly under-recognized, and outcomes associated with it are poorly understood. Methods: This is a prospective multicenter cohort study of unselected consecutive older adults admitted to 5 emergency general surgical units across the United Kingdom participating in the Older Persons Surgical Outcomes Collaboration from 2013–2014. The effect of moderate cognitive impairment defined as ≤17, bottom quartile of Montreal Cognitive Assessment was examined using multivariate logistic regression models. Primary outcome measure was the relationship between a low Montreal Cognitive Assessment score (≤17) and mortality at 30 and 90 days. Secondary outcome measures included the association between having a low Montreal Cognitive Assessment and hospital length of stay. Results: A total of 539 older patients admitted consecutively to 5 surgical units during the 2013 and 2014 study periods were included. The median age (interquartile range) was 76 years (70–82 years), the emergency operation rate was 13% (n = 72). The prevalence of cognitive impairment, using the traditional Montreal Cognitive Assessment cutoff score of ≤26, was 84.4% and, using the recently suggested cutoff score of ≤23, the prevalence was 61.0%. Multivariable analyses showed patients with a low Montreal Cognitive Assessment score (≤17) had a three-fold increase in 30-day mortality (adjusted odds ratio = 3.10; 95% confidence interval:1.19–8.11; P = .021) and an increased length of hospital stay (10 or more days; 1.80 [1.10–2.94; P = .02] and 14 or more days; 2.06 [1.17–3.61; P = .012]). Conclusion: We recommend a routine cognitive assessment in an emergency surgical setting whenever feasible to help identify patients at risk of poor outcomes.