Reliability and cross-cultural validation of the Turkish version of Manual Ability Classification System (MACS) for children with cerebral palsy

Abstract
To determine the reliability and cross-cultural validation of the Turkish translation of the Manual Ability Classification System (MACS) for children with cerebral palsy (CP) and to investigate the relation to gross motor function and other comorbidities. After the forward and backward translation procedures, inter-rater and test-retest reliability was assessed between parents, physiotherapists and physicians using the intra-class correlation coefficient (ICC). Children (N = 118, 4 to 18 years, mean age 9 years 4 months; 68 boys, 50 girls) with various types of CP were classified. Additional data on the Gross Motor Function Classification System (GMFCS), intellectual delay, visual acuity, and epilepsy were collected. The inter-rater reliability was high; the ICC ranged from 0.89 to 0.96 among different professionals and parents. Between two persons of the same profession it ranged from 0.97 to 0.98. For the test-retest reliability it ranged from 0.91 to 0.98. Total agreement between the GMFCS and the MACS occurred in only 45% of the children. The level of the MACS was found to correlate with the accompanying comorbidities, namely intellectual delay and epilepsy. The Turkish version of the MACS is found to be valid and reliable, and is suggested to be appropriate for the assessment of manual ability within the Turkish population.