Development and validation of the fall‐related injury risk in nursing homes (INJURE‐NH) prediction tool

Abstract

AbstractBackgroundExisting models to predict fall‐related injuries (FRI) in nursing homes (NH) focus on hip fractures, yet hip fractures comprise less than half of all FRIs. We developed and validated a series of models to predict the absolute risk of FRIs in NH residents.MethodsRetrospective cohort study of long‐stay US NH residents (≥100 days in the same facility) between January 1, 2016 and December 31, 2017 (n = 733,427) using Medicare claims and Minimum Data Set v3.0 clinical assessments. Predictors of FRIs were selected through LASSO logistic regression in a 2/3 random derivation sample and tested in a 1/3 validation sample. Sub‐distribution hazard ratios (HR) and 95% confidence intervals (95% CI) were estimated for 6‐month and 2‐year follow‐up. Discrimination was evaluated via C‐statistic, and calibration compared the predicted rate of FRI to the observed rate. To develop a parsimonious clinical tool, we calculated a score using the five strongest predictors in the Fine‐Gray model. Model performance was repeated in the validation sample.ResultsMean (Q1, Q3) age was 85.0 (77.5, 90.6) years and 69.6% were women. Within 2 years of follow‐up, 43,976 (6.0%) residents experienced ≥1 FRI. Seventy predictors were included in the model. The discrimination of the 2‐year prediction model was good (C‐index = 0.70), and the calibration was excellent. Calibration and discrimination of the 6‐month model were similar (C‐index = 0.71). In the clinical tool to predict 2‐year risk, the five characteristics included independence in activities of daily living (ADLs) (HR 2.27; 95% CI 2.14–2.41) and a history of non‐hip fracture (HR 2.02; 95% CI 1.94–2.12). Performance results were similar in the validation sample.ConclusionsWe developed and validated a series of risk prediction models that can identify NH residents at greatest risk for FRI. In NH, these models should help target preventive strategies.