Reliability and minimal detectable change of the <i>Challenge</i>, an advanced motor skills test for children with cerebral palsy, Danish version.

Abstract

To translate and cross-culturally adapt the <i>Challenge</i>, and investigate the reliability and minimal detectable change (MDC) of the Danish <i>Challenge</i> in children with cerebral palsy (CP). A Danish version of the <i>Challenge</i> was created through a standardized translation process. Four physiotherapists evaluated face validity. Independently ambulatory children with CP were tested. Live performance rating was conducted by assessors independently scoring the <i>Challenge</i>. Video-rating was undertaken for a subset of assessments. Same day assessment test-retest reliability was estimated. The <i>Challenge</i>'s Best Score Total was of primary interest. Forty-five children (5-18 years: mean 10 years 9 months; 19 girls) in Gross Motor Function Classification System levels I and II were tested. Inter-rater reliability was excellent for live assessments (<i>n</i> = 45) ICC = 0.998 (95% CI 0.998-0.999) and video assessments (<i>n</i> = 15) ICC = 0.991 (95% CI 0.963-0.997) and intra-rater reliability was excellent for live versus video-recorded assessments (<i>n</i> = 10) ICC = 0.977 (95% CI 0.895-0.994). Test-retest reliability (<i>n</i> = 22) was excellent with ICC = 0.991 (95% CI 0.979-0.996) and minimal detectable change (MDC₉₀) of 4.7 points. The Danish <i>Challenge</i> showed excellent reliability in this testing context when physiotherapists scored from live- or video-recorded assessments. The <i>Challenge</i>'s ability to detect 4.7 points change seems a clinically realistic target for progress. <b>Clinical trial registration:</b> This trial has been approved by the Data Protection Agency, Central Region Denmark, Ref nr.: 615216, Case nr.: 1-16-02-46-16. Registration date: 01-01-2016.Implications for rehabilitationThe <i>Challenge</i> remained reliable and maintained a promising minimal detectable change of less than five points after translation and cultural adaptation.The Danish version of the <i>Challenge</i> 20-item version can be used to measure advanced motor skill performance in children with cerebral palsy, GMFCS level I and GMFCS level II.<i>Challenge</i> live scoring is as reliable as the more time-consuming video-recorded scoring, meaning that physiotherapists can choose the method that fits best with their clinical context and preference.