Agreement and predictive value of the clinical frailty scale in hospitalized older patients.

ABSTRACT

PURPOSE: Our objective was to perform an external validity study of the clinical frailty scale (CFS) classification tree by determining the agreement of the CFS when attributed by a senior geriatrician, a junior geriatrician, or using the classification tree. Additionally, we evaluated the predictive value of the CFS for 6-month mortality after admission to an acute geriatric unit. METHODS: This prospective study was conducted in two acute geriatric units in Belgium. The premorbid CFS was determined by a senior and a junior geriatrician based on clinical judgment within the first 72 h of admission. Another junior geriatrician, who did not have a treatment relationship with the patient, scored the CFS using the classification tree. Intra-class correlation coefficient (ICC) was calculated to assess agreement. A ROC curve and Cox regression model determined prognostic value. RESULTS: In total, 97 patients were included (mean age 86 ± 5.2; 66% female). Agreement of the CFS, when determined by the senior geriatrician and the classification tree, was moderate (ICC 0.526, 95% CI [0.366-0.656]). This is similar to the agreement between the senior and junior geriatricians' CFS (ICC 0.643, 95% CI [0.510-0.746]). The AUC for 6-month mortality based on the CFS by respectively the classification tree, the senior and junior geriatrician was 0.719, 95% CI [0.592-0.846]; 0.774, 95% CI [0.673-0.875]; 0.774, 95% CI [0.665-0.882]. Cox regression analysis indicated that severe or very severe frailty was associated with a higher risk of mortality compared to mild or moderate frailty (hazard ratio respectively 6.274, 95% CI [2.613-15.062] by the classification tree; 3.476, 95% CI [1.531-7.888] by the senior geriatrician; 4.851, 95% CI [1.891-12.442] by the junior geriatrician). CONCLUSION: Interrater agreement in CFS scoring on clinical judgment without Comprehensive Geriatric Assessment is moderate. The CFS classification tree can help standardize CFS scoring.