| Affiliation: | 1. CF-Centre Copenhagen, Paediatric Pulmonary Service, Department of Paediatrics and Adolescent Medicine, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark;2. Research Unit on Women''s and Children''s Health, Copenhagen University Hospital, Rigshospitalet, Tagensvej 20, DK-2100 Copenhagen, Denmark;3. Section of Biostatistics, Department of Public Health, University of Copenhagen, Øster Farimagsgade 5, Entrance B, 2. floor, Postboks 2099, DK-1014 Copenhagen, Denmark;4. The Copenhagen City Heart Study, Frederiksberg Hospital, University of Copenhagen, Nordre Fasanvej 57, DK-2000 Frederiksberg, Denmark;5. Department of Paediatrics, Central Hospital, Lövängsvägen, 541 85 Skövde, Sweden |
| Abstract: | ![]()
BackgroundKnowledge of between-session variability of nitrogen multiple-breath washout (N2MBW) indices is crucial when designing longitudinal interventional studies and in disease monitoring using N2MBW as end-point. Such information is currently sparse.MethodsMonthly triplets of N2MBW were prospectively obtained from 14 children with CF during one year. Linear mixed models were used to analyze variability. Our aim was to assess between-session variability of N2MBW indices from repeated measurements and compare LCI derived from different software packages currently in use (TestPoint® vs. Spiroware®).ResultsBaseline LCI (median; range) was 9.37 (6.82; 12.08). Between-session differences in LCI measurements were up to 25%. Intra Class Correlation-Coefficient was 0.82. There was no systematic difference between LCI measurements derived from the two software packages (p = 0.18); however, variability was significantly higher using Spiroware®.ConclusionsWe report between-session variability of LCI using N2MBW in school-age children and adolescents with CF. LCI changes exceeding 25% may be considered clinically relevant. TestPoint® and Spiroware® can be used interchangeably in longitudinal studies. |
