External validation of approaches to prediction of falls during hospital rehabilitation stays and development of a new simpler tool

Abstract

Objectives: To test the external validity of 4 approaches to fall prediction in a rehabilitation setting (Predict-FIRST, Ontario Modifed STRATIFY (OMS), physiotherapists' judgement of fall risk (PT-Risk), and falls in the past year (Past-Falls)), and to develop and test the validity of a simpler tool for fall prediction in rehabilitation (Predict-CM2). Participants: A total of 300 consecutively-admitted rehabilitation inpatients. Methods: Prospective inception cohort study. Falls during the rehabilitation stay were monitored. Potential predictors were extracted from medical records. Results: Forty-one patients (14%) fell during their rehabilitation stay. The external validity, area under the receiver operating characteristic curve (AUC), for predicting future fallers was: 0.71 (95% confdence interval (95% CI): 0.61-0.81) for OMS (Total-Score); 0.66 (95% CI: 0.57-0.74) for Predict- FIRST; 0.65 (95% CI 0.57-0.73) for PT-Risk; and 0.52 for Past-Falls (95% CI: 0.46-0.60). A simple 3-item tool (Predict-CM2) was developed from the most predictive individual items (impaired mobility/transfer ability, impaired cognition, and male sex). The accuracy of Predict-CM2 was 0.73 (95% CI: 0.66-0.81), comparable to OMS (Total-Score) (p=0.52), signifcantly better than Predict-FIRST (p=0.04), and Past-Falls (p<0.001), and approaching signifcantly better than PT-Risk (p=0.09). Conclusion: Predict-CM2 is a simpler screening tool with similar accuracy for predicting fallers in rehabilitation to OMS (Total-Score) and better accuracy than Predict-FIRST or Past-Falls. External validation of Predict-CM2 is required.