Procedures to improve the repeatability of forced oscillation measurements in school-aged children

Respir Physiol Neurobiol. 2011 Jul 31;177(2):199-206. doi: 10.1016/j.resp.2011.02.004. Epub 2011 Feb 12.


Forced oscillation technique (FOT) parameters are less repeatable than spirometry, and the impact of technical factors, such as data acquisition and data filtering, are unknown. FOT was performed, in triplicate, on 48 children (8-11 years) and repeated two weeks later. We examined the separate effects of monitoring tidal volume (V(T)) prior to measurement and length of data acquisition on measurement repeatability. We compared the effects on repeatability of a filtering technique in which complete breaths containing respiratory artefact were rejected and statistical filters in which outlying data points were rejected. Within- and between-session repeatability of respiratory system resistance (Rrs) and reactance (Xrs) were assessed using coefficient of variation (CV) and intra-class correlation coefficient (ICC). Longer data acquisition reduced CV of Rrs and Xrs (60s vs. shorter durations, p ≤ 0.001). Monitoring V(T) reduced CV of Rrs (p = 0.05). Complete breath filtering improved CV and ICC for both Rrs and Xrs. The repeatability of FOT measurements can be improved by optimising data acquisition and filtering.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Airway Resistance / physiology
  • Child
  • Female
  • Humans
  • Male
  • Oscillometry / methods*
  • Reproducibility of Results
  • Respiratory Function Tests / methods*
  • Respiratory Mechanics / physiology