Validade de conteúdo, confiabilidade e concordância entre a avaliação presencial e por vídeo-chamada da modified bradykinesia rating scale (MBRS)

Abstract

Bradykinesia is one of the cardinal signs of Parkinson’s disease (PD), present in over 80% of individuals and associated with significant disability and reduced quality of life. It is characterized by slowness, hypokinesia, and akinesia, leading to impairments in movement speed, amplitude, and rhythm. Clinical assessment of bradykinesia has limitations, particularly in the specificity of commonly used tools. One of the most used instruments is the Movement Disorder Society – Unified Parkinson’s Disease Rating Scale (MDS-UPDRS), which includes items for a general evaluation of bradykinesia. However, it does not allow separate assessment of speed, amplitude, and rhythm. To address this limitation, the Modified Bradykinesia Rating Scale (MBRS) was developed. This clinical tool evaluates bradykinesia by separately rating speed, amplitude, and rhythm, using the same motor tasks included in the MDS-UPDRS. This is particularly important because individuals with PD may show different bradykinesia profiles, depending on which of these components are more affected. Although the MBRS shows good clinical utility, it has not been previously adapted into Brazilian Portuguese. In addition, some of its measurement properties had either not been investigated or were assessed with methodological limitations. Given the increased use of tele-rehabilitation in PD management, it is also important to examine the MBRS’s applicability in remote evaluations. This study aimed to: (1) perform a cross-cultural adaptation of the MBRS into Brazilian Portuguese; (2) assess its content validity; (3) evaluate test-retest and inter-rater reliability; and (4) analyze the agreement between in-person and video-call assessments using the MBRS. The cross-cultural adaptation followed Beaton et al. (2000) and COSMIN guidelines. For content validity, nine experts in PD assessed the instrument, and the Content Validity Index (CVI) was calculated for all evaluated items. For the reliability analyses, two examiners assessed individuals with PD using the MBRS at two time points, spaced seven to 14 days apart. On the first day, both examiners performed the evaluation; on the second, only examiner 1 repeated the assessment. The video-call evaluation was also conducted by examiner 1, seven to 14 days after the initial session. The Intraclass Correlation Coefficient (ICC) was used to assess reliability and agreement between methods. No discrepancies were found between the original and translated versions of the MBRS, indicating proper semantic and conceptual equivalence. Content validity was excellent for all criteria (CVI ≥ 0.80). Inter-rater reliability was assessed in 52 individuals (66.9 ± 6.2 years), and test-retest reliability and video-call agreement were evaluated in 50 individuals (67.1 ± 6.8 years). For all MBRS total scores (items 3.4, 3.5, 3.6, 3.8; and total speed, amplitude, rhythm, and overall score), results were acceptable: test-retest reliability (ICC = 0.464–0.745), inter-rater reliability (ICC = 0.266–0.537), and in-person vs. video-call agreement (ICC = 0.488–0.741). In conclusion, the Brazilian Portuguese version of the MBRS is semantically valid, has strong content validity, and shows acceptable reliability. It is appropriate for clinical use in both in-person and remote settings, with either the same or different raters.