Changes in lung function measured by spirometry and the forced oscillation technique in cystic fibrosis patients undergoing treatment for respiratory tract exacerbation.

Objective measures of lung function are critical for the treatment and study of lung diseases such as cystic fibrosis (CF). Spirometry is the most widely used and accepted method of pulmonary function testing in CF, but not all patients can perform the maneuvers required to obtain valid results from spirometry. The forced oscillation technique (FOT) requires less cooperation than spirometry.