Fall Injury Avoidance Strategy Scale (FIAS)-Validation of a Scale to Quantify Fall-Related Protective Movements.

Abstract

To validate the Fall Injury Avoidance Strategy Scale (FIAS), a novel video-based tool to quantify protective movements and injury risk during experimental falls among older adults. Validation study using video-recorded experimental falls from a randomized controlled trial of protective movements. Falls at baseline, postintervention, and 3-month follow-up were analyzed. Laboratory setting. Twenty-three older adults (N=23; aged 66-84y; 19 women) at risk of injurious falls. Not applicable. Participants underwent 6 standardized experimental falls in backward, left, and right directions. A total of 376 falls across study visits were recorded using motion capture and commercially available cameras. Hip and head peak acceleration were extracted using custom MATLAB scripts. The FIAS score (sum of 4 evidence-based protective fall movements; range, 0-8) and the occurrence of head impact were determined through a secondary video-based analysis by 2 independent raters using a standardized and structured scale. Interrater reliability, construct and content validity, responsiveness, and diagnostic utility of the FIAS score were evaluated. The FIAS score exhibited good interrater reliability (intraclass correlation coefficient (2,k), 0.87; 95% CI, 0.84-0.89; P<.001). Higher FIAS scores were associated with lower hip peak acceleration (B=-0.94; 95% CI, -1.33 to -0.54; P<.001) and head peak acceleration (B=-5.88; 95% CI, -6.76 to -5.01; P<.001), and lower odds of head impact (odds ratio, 0.22; 95% CI, 0.15-0.32; P<.001). FIAS also demonstrated significant responsiveness to the training-induced changes in protective movements (F=11.06; P<.001). Lastly, FIAS showed excellent diagnostic utility in identifying the risk of fall-related head impact (area under the curve, 0.87; 95% CI, 0.84-0.91), with a cut-off score of ≥5 yielding 78.03% sensitivity and 80.36% specificity. FIAS is a reliable, valid, and responsive tool for assessing the protective fall movements and injury risk among older adults, which has potential utility in the screening and prevention of fall-related injuries.