Measurement Properties and Translation to Brazilian-Portuguese of the Challenge for Children and Adolescents with Cerebral Palsy.

Aims: Translate the Challenge assessment into Brazilian-Portuguese, determine its face validity, evaluate the reliability of the total score and score per item, investigate whether the child's gross motor level (classified by the Gross Motor Function Classification System-GMFCS) influences the reliability levels, and estimate responsiveness to change.Methods: The translation followed four stages: translation, synthesis, back-translation, and review. For face validity, ten physical therapists evaluated item relevance. Children and adolescents with cerebral palsy (n = 50, 5-18 years of age) GMFCS I and II were evaluated by two therapists for inter and intra-rater reliability. Thirty of these participants were recruited for the instrument's responsiveness evaluation and reassessed (n = 28) after three months of treatment. Minimal Detectable Change (MDC), and Minimal Clinically Important Difference (MCID) were estimated.Results: The back-translated version was similar to the English version. All test items were considered relevant by the physical therapists. Total score intra and inter-rater reliability were excellent for both GMFCS levels (ICC = 0.94-0.99). Items' intra- and inter- rater reliability varied from low to almost perfect (kw=-0.14-0.94). MDC90 and MDC95 values were 3.90-6.35 and 4.63-7.54, respectively. MCID values were 3.57-4.56.Conclusion: The translated version of the Challenge showed excellent face validity and reliability and was able to document longitudinal change.