Validation of the Brazilian version of the Berg balance scale for patients with Parkinson's disease.

Background: Changes in balance occur with the progression of Parkinson's disease (PD).
Objective: To validate the Brazilian version of the Berg Balance Scale (BBS) for PD patients, determining its reliability and internal consistency and correlating it with PD-specific instruments.
Method: We evaluated 53 patients (M/F 37/16, mean age+/-SD, 62+/-7.9 years) with PD (mean+/-SD, 7.8+/-4.4 years). Unified Parkinson's Disease Rating Scale (UPDRS), Schwab and England Scale (SandE , Hoehn and Yahr Staging Scale (HY) and BBS were used to assess patients. Statistical analyses for inter-rater reliability, internal consistency and correlations among BBS, UPDRS, SandE and HY were performed.
Results: The mean scores+/-SD on UPDRS and BBS were, respectively, 41.6+/-17.8 and 47.2+/-8.2. The median on SandE and HY scales were 80% and 2.5, respectively. The BBS presented a high intra-class correlation coefficient (ICC=0.84) and internal consistency (Cronbrach's alpha=0.92). There was a statistically significant correlation between BBS and disease duration (r(s)= -0.520, p<0.001), UPDRS subscales II and III (r(s)= -0.467, p=0.011; r(s)= -0.374, p=0.046, respectively), stage of disease (HY; r(s)= -0.507, p<0.001) and the activities of daily living (SandE; r(s)=0.492, p<0.001).
Conclusion: The BBS is a promising tool for the assessment of balance in PD, correlating with the stage of disease and the level of independence.