Table 1– Comparison of population characteristics and details of equipment and methodology used by collaborating centres
CentreSubjects n (% males)Age yrsHeight cmEquipment usedQuality control (computer/manual selection)sRaw outcomesReporting of results
SoftwareMask or mouthpieceUse of filter
138 (58)7.1±1.1 (4.8–8.9)123.3±7.8 (109–141)V4.1MouthpieceIn specific patient groupsComputer and manualsRtot and sReffWeighted mean
240 (50)4.5±1.0 (2.6–6.0)107.5±10.3 (88–127)V4.22 and V4.34Specialised maskNoComputersRtotMean of median
3828 (55)5.1±1.0 (2.5–7.0)111.6±8.1 (88–155)V4.34MouthpieceNoManualsRtotMedian of first set of acceptable loops
4472 (51)6.6±2.1 (2.7–11.0)120.3±14.5 (89–159)V4.65 and 5.01MouthpieceyesComputersRtot and sReffWeighted mean, mean of medians and median
51494 (53)4.2±1.0 (3.0–5.0)104.3±8.2 (87–126)V4.34 and 4.65MaskyesComputersReffMean of median
  • Data are presented as mean±sd (range), unless otherwise indicated. sRaw: specific airways resistance; V: version; sRtot: specific total resistance; sReff: specific effective resistance.