Performance‐based balance tests, combined with the number of falls recalled in the past year, predicts the incidence of future falls in established unilateral transtibial prosthesis users

Abstract

Falls are common and consequential events for lower limb prosthesis (LLP) users. Currently, there are no models based on prospective falls data that clinicians can use to predict the incidence of future falls in LLP users. Assessing who is at risk for falls, and thus most likely to need and benefit from intervention, remains a challenge. To determine whether select performance-based balance tests predict future falls in established, unilateral transtibial prosthesis users (TTPU). Multisite prospective observational study. Research laboratory and prosthetics clinic. Forty-five established, unilateral TTPU. Not applicable. The number of falls reported over a prospective 6-month period. Timed Up-and-Go (TUG) and Four-Square Step Test (FSST) times, as well as Narrowing Beam Walking Test scores were recorded at baseline, along with the number of falls recalled over the past 12 months and additional potential fall-risk factors. The final negative binomial regression model, which included TUG (P = .044) and FSST (P = .159) times, as well as the number of recalled falls (P = .009), was significantly better than a null model at predicting the number of falls over the next 6 months (X2 [3] = 11.6, P = .009) and fit the observed fall count data (X2 [41] = 36.12, P = .20). The final model provided a significant improvement in fit to the prospective fall count data over a model with fall recall alone X2 (1) = 4.342, P < .05. No combination of performance-based balance tests alone predicted the incidence of future falls in our sample of established, unilateral TTPU. Rather, a combination of the number of falls recalled over the past 12 months, along with TUG and FSST times, but not NBWT scores, was required to predict the number of "all-cause" falls over the next 6months. The resulting predictive model may serve as a suitable method for clinicians to predict the incidence of falls in established, unilateral TTPU.