Figure 1.

Summary of study population. Multiple breath washout tests were considered technically acceptable according to quality control review criteria (31) and if there were at least two technically acceptable trials in a test occasion. Percentages are calculated based on the total number of visits expected (468 cystic fibrosis, 438 healthy control subjects), with the exception of the percentage successful, which is calculated as number technically acceptable/number analyzed. CF = cystic fibrosis subjects; HC = healthy control subjects; MBW = multiple breath washout.