PT  - JOURNAL ARTICLE
AU  - Kent Green
AU  - Thomas Kongstad
AU  - Frederik Buchvald
AU  - Marianne Skov
AU  - Tania Pressler
AU  - Per Gustafsson
AU  - Kim G. Nielsen
TI  - Short and long term repeatability of N2 multiple breath washout indices in children with cystic fibrosis
DP  - 2013 Sep 01
TA  - European Respiratory Journal
PG  - P1097
VI  - 42
IP  - Suppl 57
4099  - http://erj.ersjournals.com/content/42/Suppl_57/P1097.short
4100  - http://erj.ersjournals.com/content/42/Suppl_57/P1097.full
SO  - Eur Respir J2013 Sep 01; 42
AB  - Rationale:Multiple breath washout (MBW) is increasingly used as a highly sensitive endpoint in cystic fibrosis (CF) studies. However, repeatability of output variables such as Lung Clearance Index (LCI) and the clinical indices Scond and Sacin in children with CF (Respiration 2009; 78: 339) are sparsely reported despite being essential prerequisites to implementation in studies of lung disease. We assessed within and between occasion repeatability in CF children during one year.Methods:N2 MBW (Exhalyzer D, EcoMedics AG) in triplets was prospectively performed every month during one year in eight children excluding occasions with clinical pulmonary exacerbations and less than two acceptable trials. Within occasion (Wo) and between occasion (Bo) repeatability of LCI, Scond and Sacin were expressed as SD and CV%.Results:Ninety-eight test occasions were performed and 90% fulfilled inclusion criteria. Mean (SD) LCI, Scond and Sacin of all tests: 9.01 (1.73), 0.071 (0.031) and 0.090 (0.025), respectively. Estimates (SD) of Bo repeatability of LCI, Scond and Sacin suggest that changes > 1.55, 0.027 and 0.064 units (mean + 1.96 SD), respectively, could be regarded significant.Conclusion:We reported estimates of short- and long-term repeatability of N2 MBW indices in children with CF. These estimates are essential prerequisites to future studies of CF lung disease using N2 MBW variables as primary outcome parameters.View this table: