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

Abstract

Purpose

To translate and cross-culturally adapt the Challenge, and investigate the reliability and minimal detectable change (MDC) of the Danish Challenge in children with cerebral palsy (CP).

Materials and methods

A Danish version of the Challenge 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 Challenge. Video-rating was undertaken for a subset of assessments. Same day assessment test–retest reliability was estimated. The Challenge’s Best Score Total was of primary interest.

Results

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 (n = 45) ICC = 0.998 (95% CI 0.998–0.999) and video assessments (n = 15) ICC = 0.991 (95% CI 0.963–0.997) and intra-rater reliability was excellent for live versus video-recorded assessments (n = 10) ICC = 0.977 (95% CI 0.895–0.994). Test–retest reliability (n = 22) was excellent with ICC = 0.991 (95% CI 0.979–0.996) and minimal detectable change (MDC₉₀) of 4.7 points.

Conclusions

The Danish Challenge showed excellent reliability in this testing context when physiotherapists scored from live- or video-recorded assessments. The Challenge’s ability to detect 4.7 points change seems a clinically realistic target for progress. Clinical trial registration: 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 rehabilitation

• The Challenge remained reliable and maintained a promising minimal detectable change of less than five points after translation and cultural adaptation.

• The Danish version of the Challenge 20-item version can be used to measure advanced motor skill performance in children with cerebral palsy, GMFCS level I and GMFCS level II.

• Challenge 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.

Keywords:

• Gross motor function
• psychometric properties
• disabilities
• ambulatory children
• cerebral palsy

Acknowledgements

Thanks, to the research team at Bloorview Research Institute Toronto, Canada for collaboration to fulfill our task, while the development of the original Challenge, was still going on. Thanks to all the children and their parents, who gave their time and contributed with great enthusiasm by participating into this study, it was fun. Thanks to Trine Friis Gehlert, Michael Overgaard, and Lone Nielsen for working with testing, to professional’s participation into the translation processes and also Therese Koops Groenborg for help, advice, and guidance on statistics, who all together have contributed to get this work done. Funding of this study was with donations from the Danish Physiotherapist Research Foundation and from Health Research foundation Central Region Denmark. Authors have stated their disclosures.

Disclosure statement

One of the authors F. Virginia Wright is the lead developer of the original English version of the Challenge measure. This author do not have any personal financial interest in the measure, i.e., do not receive any money or other compensation from its sharing and use.

Data availability statement

The Challenge material in Danish is only available after training and passing the online criterion calibration. Contact F. Virginia Wright PT, PhD, Bloorview Research Institute for further information, [email protected], or Kirsten Nordbye-Nielsen, Aarhus University Hospital Denmark, [email protected]. This study was conducted at the Department of Children’s Orthopedics, Aarhus University Hospital, Denmark.