We would like to sincerely thank Mosadeseh Sani and Erfan Ayubi for the interest in our paper . The main aim of this study was to investigate the relationship between lung function and exercise performance in adults with CF. We feel that our study elegantly shows the non-linear relationship between lung function and distance walked after performing the incremental shuttle test (MST).
Our secondary aim was to develop a CF-specific equation to predict MST performance. The multivariate regression analysis showed that in patients with FEV1 <67%, males walked approximately 280 m further than females; with every additional year of age, patients walked 9 m less; and with every 1% decrease in lung function, patients walked 15 m less. We think this delivers important clinical and useful information for physiotherapists working with adults with CF. We acknowledge the comment of the authors about cross-validation and invite these and other researchers to cross-validate our regression equation in another sample of CF patients.
Response to letter to the editor re ‘Relationship between exercise test performance and lung function in CF’