Commentary on "Developmental Trajectories and Reference Percentiles for the 6-Minute Walk Test for Children With Cerebral Palsy".

Abstract

“How should I apply this information?” This study is a secondary analysis of 2 large, high-quality longitudinal datasets tracking the developmental trajectories of children with cerebral palsy (CP). The study's results suggest that individual children's 6-minute walk test (6MWT) performance can vary vastly at different time points, and still be interpreted as “progressing as expected.” Thus, it is not clear how the test provides meaningful information for children, their families, or clinicians. The high degree of intrachild variability over time is surprising, and it is unclear what is contributing to this. It is possible that the study's 6MWT administration procedure (which differed from conventional 6MWT protocols in the lack of a practice walk, lack of standardized verbal praise, and use of creativity to achieve compliance) and child factors (eg, pain, fitness, fatigue, or motivation) may be contributing. “What should I be mindful about when applying this information?” Giving children and parents messages-relating performance to percentiles has the potential to be a negative experience, particularly if children's performance places them below average. Children with CP have motor delays in comparison to their peers, and being told they are also behind their comparable CP peers may be demoralizing. Based on the information presented, incorporating the 6MWT into clinical practice is of limited benefit, and does not justify the time/effort and possible harms. The study focuses on using the 6MWT to predict future 6MWT performance. The 6MWT may be a more useful prognostic tool if its performance can be shown to reliably predict other more clinically useful outcomes. Carol Maher, BPT (Hons), PhD University of South Australia Adelaide, Australia Kerrie Kuszczakowski, BPT Novita Children's Services Adelaide, Australia