Prognostic Association Between Frailty and Post-Arrest Health Outcomes in Patients Receiving Home Care: A Population-Based Retrospective Cohort Study

Aim: To evaluate the association between frailty and post-cardiac arrest survival, functional decline, and cognitive decline, among patients receiving home care. Methods: Frailty was measured using the Clinical Frailty Scale (CFS) and a valid frailty index. We used multivariable logistic regression to measure the association between frailty and post-arrest outcomes after adjusting for age, sex, and arrest setting. Functional independence and cognitive performance were measured using the interRAI ADL Long-Form and Cognitive Performance Scale, respectively. We conducted sub-group analytics of in-hospital and out-of-hospital arrests. Results: Our cohort consisted of 7,901 home care clients; most patients arrested out-of-hospital (55.4%) and were 75 years or older (66.3%). Most were classified as frail (94.2%) with a CFS score of 5 or greater. The 30-day survival rate was higher for in-hospital (26.6%) than out-of-hospital cardiac arrests (5.2%). Most patients who survived to discharge had declines in post-arrest functional independence (65.8%) and cognitive performance (46.5%). A one-point increase in the CFS decreased the odds of 30-day survival by 8% (aOR = 0.92; 95%CI = 0.87-0.97). A 0.1 unit increase in the frailty index reduced the odds of 30-day survival by 9% (aOR = 0.91; 95%CI = 0.86-0.96). The frailty index was associated with declines in functional independence (OR = 1.16; 95%CI = 1.02-1.31) and cognitive performance (OR = 1.24; 95%CI = 1.09-1.42), while the CFS was not. Conclusion: Frailty is associated with cardiac arrest survival and post-arrest cognitive and functional status in patients receiving home care. Postcardiac arrest cognitive and functional status are best predicted using more comprehensive frailty indices.