Clinical Frailty Scale and Comorbidity-Polypharmacy Score for prediction of 30-day mortality in a mixed ICU population.

Objective: To investigate the prediction of 30-day mortality by frailty and comorbidity in a mixed ICU population and monitor the implementation of the Clinical Frailty Scale as daily practice in the ICU.

Design: A prospective observational single-center cohort study.

Setting: Mixed ICU at Zealand University Hospital.

Patients: All patients >40 years of age acutely admitted to the ICU from April 1st 2021 to March 31st 2022.

Main variables of interest: Frailty assessed by the Clinical Frailty Scale (CFS), Comorbidity-Polypharmacy-Score (CPS), and 30-day mortality.

Results: A total of 319 patients were included in the study. Of these, 118 (37%) were categorized as frail, defined by a CFS ≥ 5. The CPS score was median (IQR) 13 (7-18), rated as moderate. Patients with increasing frailty demonstrated higher CPS scores. The overall 30-day mortality was 34.5%. Patients categorised as frail had a higher 30-day mortality compared to non-frail patients (47% vs 27%). The AUROC of CFS and CPS of 30-day mortality was 0.77 (95% CI 0.72 to 0.83) and 0.75 (95% CI 0.69 to 0.81), respectively. Combining CFS and CPS did not strengthen the ability to predict 30-day mortality compared to CFS alone. ICU clinicians assessed CFS in 79% of patients.

Conclusion: Frailty assessed by CFS had a fair prediction of 30-day mortality after ICU admission in a mixed ICU population. The discriminatory ability for predicting 30-day mortality was not improved by combining CFS and CPS compared to CFS alone. The clinical implementation of the CFS was performed effectively.