Minimal clinically important difference of the Berg Balance Scale and comfortable walking speed in patients with acute stroke: A multicenter, prospective, longitudinal study

Abstract

Objective To determine the minimal clinically important difference between the Berg Balance Scale and comfortable walking speed in acute-phase stroke patients. Design Multicenter, prospective, longitudinal study. Setting Inpatient acute stroke rehabilitation. Subjects Seventy-five patients with acute stroke, mean (SD) age 71.7 (12.2) years. Intervention Inpatients with acute stroke were assessed with the Berg Balance Scale and comfortable walking speed before and after rehabilitation. Physiotherapy was conducted to improve balance and gait over a 2-week period: an average of 40 min/day on weekdays and 20 min/day on weekends and holidays. Main measures The patients’ Berg Balance Scale, comfortable walking speed, Global Rating of Change scale (patient-rated and physiotherapist-rated), and motor score of the Functional Independence Measure were obtained. Minimal clinically important differences were estimated using both anchor- (receiver operating characteristic curves and change difference) and distribution-based approaches (minimal detectable change and 0.5× the change score [SD]). Results The baseline scores were 31.2 (18.9) for the Berg Balance Scale and 0.79 (0.35) m/s for comfortable walking speed. The minimal clinically important difference in the Berg Balance Scale was 6.5–12.5 points by the anchor-based approach and 2.3–4.9 points by the distribution-based approach. The minimal clinically important difference in comfortable walking speed was 0.18–0.25 m/s by the anchor-based and 0.13–0.15 m/s by the distribution-based approach. Conclusions A change of 6.5–12.5 points in the Berg Balance Scale and 0.18–0.25 m/s in the comfortable walking speed is required in these measurements’ anchor-based minimal clinically important differences to be beyond measurement error, and to be perceptible by both patients and clinicians.