Comparing How Three Frailty Scales Predict Negative Outcomes in Trauma Patients With Rib Fractures

Frailty is a risk factor for adverse outcomes after injury. Herein, we compared three frailty scales: the Canadian Study of Health and Aging clinical frailty scale, the rib fracture frailty index (RFFI) and the modified frailty index-5, to assess which scale is most applicable in predicting risk for negative outcomes in older patients with rib fractures.

Patients ≥65 admitted for rib fractures were retrospectively scored for frailty using the RFFI, Canadian Study of Health and Aging clinical frailty scale, and modified frailty index-5. Outcomes examined were in-hospital mortality, pneumonia, in-hospital intubation, hospital length of stay, and discharge to skilled nursing facilities. Areas under the curve, sensitivity, specificity, negative predictive value, and positive predictive value were determined for each frailty scale with each outcome. Agreement was determined using Fleiss' Kappa. P <0.05 was considered significant.

Three hundred forty-one patients were included. All three scales demonstrated similar predictive abilities for the measured outcomes. RFFI predicted mortality and pneumonia 70% of the time. All three scales predicted discharge to skilled nursing facilities 60% of the time. The concordance for all three frailty scales was 241/341 (70.7%). Fleiss Kappa was 0.40 [0.34-0.46] (P < 0.001), indicating a fair to moderate agreement. The predictive ability of all three scales was higher in patients 65-74 y old than in patients ≥75.

Overall, no scale appeared to significantly outperform the others by areas under the curve estimation. Interrater reliability was higher in the 65 to 74-y-old population compared to the 75 and older population.