Validity and reliability of an automated fall risk assessment system using a depth camera in community-dwelling adults: A proof-of-concept pilot study

Abstract

Background

Clinical fall risk prediction often relies on subjective observation or simplistic metrics, despite the high costs associated with falls in older adults.

Objective

This proof-of-concept study evaluated the validity and reliability of a consumer-grade depth camera system as an objective alternative for automated fall risk assessment.

Methods

Thirty-nine community-dwelling adults performed Timed Up and Go (TUG), Five Times Sit-to-Stand (FTSS), and Tandem Stance (TST) tests. Concurrent measurements were taken by an automated depth camera and blinded physical therapists. Validity (concurrent, convergent, discriminative) and reliability were assessed.

Results

Automated FTSS and TUG tests demonstrated strong concurrent validity with therapist measurements (r = 0.813 and 0.915) and high discriminative accuracy for fall history (AUC = 0.941 and 0.864). Depth camera-based FTSS vertical velocity was significantly lower in participants with a fall history (p < 0.001). TST sway metrics showed limited discriminative validity. The system showed good to excellent test-retest reliability. In an age-stratified analysis of older adults (≥65 years), AFTSS time and the AUC-weighted composite score demonstrated acceptable discrimination for retrospective fall history (AUC = 0.892 and 0.867, respectively)

Conclusions

The depth camera system showed promise as a valid and reliable tool for objective quantification of performance on fall-risk-related functional tests, particularly FTSS and TUG, when benchmarked against therapist-administered measurements. Discriminative findings against retrospective fall history should be interpreted as exploratory, and larger prospective studies are required before clinical screening thresholds can be recommended.

Trial Registration

ClinicalTrials.gov (NCT06519864).