Minimal Clinically Important Difference of Berg Balance Scale in People With Multiple Sclerosis

Abstract

Objective: To identify the minimal clinically important difference (MCID) to define clinically meaningful patient's improvement on the Berg Balance Scale (BBS) in people with multiple sclerosis (PwMS) in response to rehabilitation.

Design: Cohort study.

Setting: Neurorehabilitation institute.

Participants: PwMS (N=110).

Interventions: This study comprised inpatients and outpatients who participated in research on balance and gait rehabilitation. All received 20 rehabilitation sessions with different intensities. Inpatients received daily treatments over a period of 4 weeks, while outpatients received 2 to 3 treatments per week for 10 weeks.

Main outcome measures: An anchor-based approach using clinical global impression of improvement in balance (Activities-specific Balance Confidence [ABC] Scale) was used to determine the MCID of the BBS. The MCID was defined as the minimum change in the BBS total score (postintervention - preintervention) that was needed to perceive at least a 10% improvement on the ABC Scale. Receiver operating characteristic curves were used to define the cutoff of the optimal MCID of the BBS discriminating between improved and not improved subjects.

Results: The MCID for change on the BBS was 3 points for the whole sample, 3 points for the inpatients, and 2 points for the outpatients. The area under the curve was .65 for the whole sample, .64 for inpatients, and .68 for outpatients.

Conclusions: The MCID for improvement in balance as measured by the BBS was 3 points, meaning that PwMS are likely to perceive that as a reproducible and clinically important change in their balance performance.

Keywords: Multiple sclerosis; Patient outcome assessment; Postural balance; Rehabilitation.