Tele-Assessment of the Berg Balance Scale: Effects of Transmission Characteristics.

Objective: To compare Berg Balance Scale (BBS) rating using videos with differing transmission characteristics with direct in-person rating.

Design: Repeated-measures study for the assessment of the BBS in 8 configurations: in person, high-definition video with slow motion review, standard-definition videos with varying bandwidths and frame rates (768 kilobytes per second [kbps] videos at 8, 15, and 30 frames per second [fps], 30 fps videos at 128, 384, and 768 kbps).

Setting: Medical center.

Participants: Patients with limitations (N=45) in ≥1 of 3 specific aspects of motor function: fine motor coordination, gross motor coordination, and gait and balance.

Interventions: Not applicable.

Main Outcomes Measures: Ability to rate the BBS in person and using videos with differing bandwidths and frame rates in frontal and lateral views.

Results: Compared with in-person rating (7%), 18% (P=.29) of high-definition videos and 37% (P=.03) of standard-definition videos could not be rated. Interrater reliability for the high-definition videos was .96 (95% confidence interval, .94-.97). Rating failure proportions increased from 20% in videos with the highest bandwidth to 60% (P<.001) in videos with the lowest bandwidth, with no significant differences in proportions across frame rate categories. Both frontal and lateral views were critical for successful rating using videos, with 60% to 70% (P<.001) of videos unable to be rated on a single view.

Conclusions: Although there is some loss of information when using videos to rate the BBS compared to in-person ratings, it is feasible to reliably rate the BBS remotely in standard clinical spaces. However, optimal video rating requires frontal and lateral views for each assessment, high-definition video with high bandwidth, and the ability to carry out slow motion review.