Background: The Modified Shuttle Test (MST) is a valid and sensitive measure of exercise capacity in adult CF patients. Recently, its validity in children has been demonstrated. The aim of this study was to demonstrate the utility of the MST as a measure of responsiveness to hospitalisation for i.v. antibiotic and supportive therapy in children and adolescents with CF.
Methods: 28 children and adolescents (40 admissions) performed a MST and lung function within 48 h of admission and discharge to hospital for administration of intravenous antibiotics. Mean age was 12.7 years and antibiotic therapy length was 14.7 days.
Results: Upon admission, the mean (S.D.) FEV(1) was 63 (19)% predicted, FVC was 80 (18)% predicted, FEF(25-75) 43 (29)% predicted and MST distance 718 (232) m. FEV(1) increased by 15% (p<or=0.001), FVC by 13% (p<or=0.001), FEF(25-75) by 39% (p<or=0.001) and MST distance by 102 m (p<or=0.001). The percentage improvement in MST distance at 18% (p<or=0.001) was similar to that for FEV(1), but could not be predicted by the change in FEV(1).
Conclusion: This study demonstrated the utility of the MST to assess the effect of hospitalisation for i.v. antibiotic and supportive therapy in children and adolescents with CF.