Performance of 3 frailty scales for predicting adverse outcomes at 30 days in older patients discharged from emergency departments.

Objectives: To compare the ability of 3 frailty scales (the Clinical Frailty Scale [CFS], the Functional Index - eMergency [FIM], and the Identification of Seniors at Risk [ISAR] scale) to predict adverse outcomes at 30 days in older patients discharged from hospital emergency departments (EDs).

Material and methods: Secondary analysis of data from the FRAIL-Madrid registry of patients aged 75 years or older who were discharged from Madrid EDs over a period of 3 months in 2018 and 2019. Frailty was defined by a CFS score over 4, a FIM score over 2, or an ISAR score over 3. The outcome variables were revisits to an ED, hospitalization, functional decline, death, and a composite variable of finding any of the previously named variables within 30 days of discharge.

Results: A total of 619 patients were studied. The mean (SD) age was 84 (7) years, and 59.1% were women. The CFS identified as frail a total of 339 patients (54.8%), the FIM 386 (62.4%), and the ISAR 301 (48.6%). An adverse outcome occurred within 30 days in 226 patients (36.5%): 21.5% revisited, 12.6% were hospitalized, 18.4% experienced functional decline, and 3.6% died. The areas under the receiver operating characteristic curves were as follows: CFS, 0.66 (95% CI, 0.62-0.70; P = .022); FIM, 0.67 (95% CI, 0.62-0.71; P = .021), and ISAR, 0.64 (95% CI, 0.60-0.69; P = .023). Adjusted odds ratios (aOR) showed that frailty was an independent risk factor for presenting any of the named adverse outcomes: aOR for CFS >4, 3.18 (95% CI, 2.02-5.01), P .001; aOR for FIM > 2, 3.49 (95% CI, 2.15-5.66), P .001; and aOR for ISAR >3, 2.46 (95% CI, 1.60-3.79), P .001.

Conclusion: All 3 scales studied - the CFS, the FIM and the ISAR - are useful for identifying frail older patients at high risk of developing an adverse outcome (death, functional decline, hospitalization, or revisiting the ED) within 30 days after discharge.