Interrater Reliability of the Berg Balance Scale When Used by Clinicians of Various Experience Levels to Assess People With Lower Limb Amputations

Abstract

People with lower limb amputations frequently have impaired balance ability. The Berg Balance Scale (BBS) has excellent psychometric properties for people with neurologic disorders and elderly people dwelling in the community. A Rasch analysis demonstrated the validity of the BBS for people with lower limb amputations of all ability strata, but rater reliability has not been tested. The study objective was to determine the interrater reliability and intrarater reliability of BBS scores and the differences in scores assigned by testers with various levels of experience when assessing people with lower limb amputations. This reliability study of video-recorded single-session BBS assessments had a cross-sectional design. From a larger study of people with lower limb amputations, 5 consecutively recruited participants using prostheses were video recorded during an in-person BBS assessment. Sixteen testers independently rated the video-recorded assessments. Testers were 3 physical therapists, 1 occupational therapist, 3 third-year and 4 second-year doctor of physical therapy (DPT) students, and 5 first-year DPT students without clinical training. Rater reliability was calculated using intraclass correlation coefficients (ICC [2,k]). Differences in scores assigned by testers with various levels of experience were determined by use of an analysis of variance with Tukey post hoc tests. The average age of the participants was 53.0 years (SD=15.7). Amputations had occurred at the ankle disarticulation, transtibial, and transfemoral levels because of vascular, trauma, and medical etiologies an average of 8.2 years earlier (SD=7.9). Berg Balance Scale scores spanned all ability strata. Interrater reliability (ICC [2,k]=.99) and intrarater reliability of scores determined in person and through video-recorded assessments by the same testers (ICC [2,k]=.99) were excellent. For participants with the lowest levels of ability, licensed professionals assigned lower scores than did DPT students without clinical training. Intrarater reliability calculations were based on 2 testers. Berg Balance Scale scores assigned to people using prostheses by testers with various levels of clinical experience had excellent interrater reliability and intrarater reliability.