Translation and cross-cultural adaptation of the Charcot-Marie-Tooth disease Pediatric Scale to Brazilian Portuguese and determination of its measurement properties.

BACKGROUND: The Charcot-Marie-Tooth disease Pediatric Scale (CMTPedS) has been used to measure aspects of disability in children with all types of Charcot-Marie-Tooth disease (CMT).

OBJECTIVE: To translate and cross-culturally adapt the CMTPedS into Brazilian-Portuguese and determine its reliability and validity.

METHODS: The translation and cross-cultural adaptation followed international guidelines recommendations. Twenty individuals with CMT were assessed. Two examiners assessed the participants for inter-rater reliability. Face validity was assessed by eight physical therapists that judged the relevance of each test item. The Bland-Altman analysis (bias) and standard error of measurement (SEM) complemented the analysis. Furthermore, intraclass correlation coefficients (ICC), weighted kappa (k), and internal consistency (Cronbach's alpha) was determined.

RESULTS: The CMTPedS was successfully translated and cross-culturally adapted. Twenty children/youth were enrolled in the study. Of these, the majority (55%) were girls with a mean age of 13.9 (range: from 6 to 18) years. Regarding face validity, the CMTPedS-Br showed relevant items for assessing children and youth with CMT. The ICC for the total score showed excellent reliability (ICC2.1  = 0.93, 95% CI = 0.84, 0.97). The most reliable items were grip, dorsiflexion and plantar flexion strength while the least reliable items were pinprick, vibration, and gait. The internal consistency was excellent (α = 0.96, 95% CI = 0.91, 0.99) and the agreement showed small variability (bias = 0.15, 95% CI= -4.28, 4.60).

CONCLUSION: The CMTPedS-Br showed adequate reliability and face validity to measure disability in individuals with CMT. This tool will allow Brazil to be part of multicentered studies on such a rare but debilitating condition.