Assessing Fall Risk in Older Adults: The Role of Reaction Time and Inhibitory Control Testing with ReacStick.

Abstract

To determine whether ReacStick parameters can differentiate between recurrent fallers and non-fallers and compare its diagnostic precision with functional tests. Cross-sectional study SETTING: Outpatient Rehabilitation Clinic in a Tertiary Hospital PARTICIPANTS: Community-dwelling older adults were recruited using convenience sampling. Ninety participants were enrolled, with those having recurrent falls (> 1 time) in the prior year age- and sex-matched with non-fallers. Not applicable. Sensorimotor functions (visual acuity, vibratory sensation, knee extensor strength), cognition, Timed Up and Go (TUG), and Berg Balance Scale (BBS) were evaluated. ReacStick parameters, which assessed Simple Reaction Time (SRT) using ruler-drop method and Reaction Accuracy by requiring participants to grasp or release the device within 390 milliseconds based on a light cue, were collected. The percentage of correctly caught light on trials (ON Accuracy), correctly released light off trials (OFF Accuracy), and the combination (All Accuracy) were recorded. Group comparisons and Receiver Operating Characteristic (ROC) curves were used to assess the ability of the parameters to discriminate between fallers and non-fallers. Multivariate logistic regression identified independent variables for faller status. Recurrent fallers showed significantly worse SRT, OFF Accuracy, All Accuracy, and OFF accuracy/SRT. Highest area under the curves were observed for All Accuracy (0.80), OFF Accuracy/SRT (0.79), and OFF accuracy (0.76). OFF accuracy/SRT best predicted faller status [aOR=12.18, 95% CI: 3.75-39.53]. TUG and BBS showed non-significant trends, while knee extensor strength was protective (aOR=0.53, 95% CI: 0.29-0.97). Diminished short latency inhibitory control was the most accurate means to identify faller status, whereas good knee extensor strength showed a protective effect. ReacStick may offer potential as a sensitive tool for assessing short latency inhibitory control and processing speed related to faller status in older adults. When combined with strength assessment, incorporating ReacStick in clinical practice may improve the accuracy of fall-status classification. TCTR20240828002.