Table 1

Group characteristics of reference population according to centre and equipment

EquipmentJaegerRASP
centreLondon, UKNewcastle, AustraliaBarcelona-Donostia, SpainLisbon, PortugalALLLondon, UK
Subjects, n114185511198231
Boys45%61%44%82%48%52%
White infants76%83%100%100%84%91%
Test occasions, n206188811323316
Postnatal age* (w)50.7 (8–112)56.4 (15–112)73.2 (21–104)57.9 (45–118)52.2 (8–118)7.7 (4–59)
Length* (cm)75.5 (54.1–92.5)76.8 (57.2–85.9)79.0 (54–86.8)78.0 (71.5–84.5)75.9 (54–92.5)57.9 (50.2–78.8)
z-Length†0.76 (0.94)−0.24 (1.29)0.10 (1.17)−0.04 (1.3)0.50 (1.10)0.25 (1.04)
z-Weight†0.32 (0.92)0.20 (1.38)0.14 (0.95)−0.02 (0.90)0.25 (0.96)−0.13 (0.92)
Smoking in pregnancy12%22%7%18%12%36%
Postnatal smoking exposure15%67%15%36%18%44%
  • *Median (range).

  • †Mean (SD) according to UK-WHO reference range for term infants.25

  • RASP, Respiratory Analysis Software Program; z, z-scores.