Frailty is a better predictor than age for shockable rhythm and survival in Out-of-Hospital cardiac arrest in over 16-year-olds

Objective: To determine if the Clinical Frailty Scale (CFS) predicts out-of-hospital cardiac arrest (OHCA) outcomes better than age?Design: The analysed data was collected as part of a larger study run by NCEPOD on hospital admissions for OHCA in 2018. Study selection was OHCA in over 16-year-olds with restoration of spontaneous circulation (ROSC) for >20 mins and who were admitted to hospital, or who died in the emergency department. Patients from hospitals in England, Wales and Northern Ireland were identified using standard coding for cardiac arrest. CFS, age and gender were examined against two binary outcomes (non-shockable rhythm and survival) Results: 304 patients with a known CFS, known original rhythm, and known outcome were included. Younger patients had lower CFSs, as a continuous variable (Pearson correlation coefficient 0.44, p-value < 0.001) and in CFS groupings of 1–3, 4–6, 7–9 (p-value < 0.001). CFSs were higher (p-values < 0.001) for both non-shockable rhythm and death (median CFS was 4 for death and 2 for survivors). Logistic regression analysis of continuous scale CFS showed the association with non-shockable rhythm remained when adjusted for age and sex (odds ratio [95% CI]; age adjustment 1.46 [1.28, 1.68] p-value < 0.001) and remained for survival when adjusted for age alone (odds ratio [95% CI]; 1.60 [1.36, 1.88] p-value < 0.001) and when adjusted for age, sex and initial rhythm combined (1.45 [1.21, 1.73] p-value < 0.001). 3.2% of patients had resuscitation against their advanced-care-directives. 12.9% (23/178) of hospitals had electronic systems which shared advance-care-directives with ambulance services and primary care. Conclusion: A higher CFS is a prognostic indicator in adult OHCA independent of age. Frail individuals have a lower likelihood of a shockable rhythm and poorer survival. Sensitive sharing of this information with patients when discussing advance-care-directives may enhance shared decision-making