The Six-Minute Walk Test Cannot Predict Peak Cardiopulmonary Fitness in Ambulatory Adolescents and Young Adults With Cerebral Palsy

ObjectivesTo determine whether the 6-minute walk test (6MWT) is predictive of peak oxygen consumption (Vo2peak) and whether the 6MWT is a clinically applicable alternative to cardiopulmonary exercise testing (CPET) in ambulatory adolescents and young adults with cerebral palsy (CP).DesignCross-sectional.SettingUniversity hospital and rehabilitation centers.ParticipantsAdolescents and young adults with CP (N=41) classified in Gross Motor Function Classification System (GMFCS) level I or II.InterventionsNot applicable.Main Outcome MeasuresThe covered distance during 6 minutes was measured with a 6MWT. The Vo2peak was obtained with CPET on a cycle ergometer.ResultsUnivariate linear regression analysis was used to study the relationship between the outcomes of both tests. A multiple linear regression analysis was performed to determine whether Vo2peak could be predicted by the 6MWT, sex, body mass, and GMFCS level. A significant relationship (P<.01) was found between the outcomes of the 6MWT and CPET, with an explained variance of 21%. The multiple linear regression analysis showed an explained variance of 58% and a standard error of estimate (SEE) corresponding to 18% of the mean Vo2peak.ConclusionsThe 6MWT is poorly related to Vo2peak in ambulatory adolescents and young adults with CP. Because of a high SEE, the multiple regression model did not allow for prediction of Vo2peak from the 6MWT in ambulatory adolescents and young adults with CP.