Use of videotape to assess mobility in a controlled randomized crossover trial of physiotherapy in chronic multiple sclerosis

Abstract

Objectives: To determine to what degree assessment of mobility based on comparison of videotape recordings before and after courses of physiotherapy in patients with chronic multiple sclerosis (MS) is reliable, correlates with 'live' assessments and indicates benefit.

Design: Prospective data collection within a randomized crossover controlled trial of physiotherapy at home, as an outpatient, or 'no therapy' in 40 patients.

Setting: Hospital outpatients: outpatient and home physiotherapy.

Outcomes: Mobility change based on a comparison of short video recordings before and after each treatment period was scored independently by two physiotherapists blinded to therapy type and other measures of outcome. Scores were compared with changes in the Rivermead Mobility Index (RMI) and other indices assessed by a physiotherapist in the patient's home.

Results: The two video observers agreed substantially on patient outcome. Changes in walking based on video correlated with RMI for home treatment (r = 0.41, p = 0.008) but not for hospital or no treatment periods (r = 0.14 and 0.15): video changes correlated with the 'live' assessor's global change score inconsistently ('no therapy' r = 0.48, p = 0.002, hospital r = 0.30, p = 0.06 and home r = 0.17, p = 0.30 treatment periods). Based on video data alone, improved mobility was evident following home therapy for only one observer but not for the other or the averaged scores of both.

Conclusion: There was substantial agreement between two observers deciding on change in mobility based on independent blinded evaluation of short video sequences. However the correlations of these with 'live' assessments were variable. Physiotherapy had a less clear benefit on mobility based on video analysis alone compared with 'live' assessments. The study highlights the need for more objective measures of habitual mobility over longer periods.