Infant characteristics by test occasion
| First test1-150 | Second test1-150 | Mean (95% CI)1-151 within-subject difference between second and first test | |
| Postnatal age (weeks) | 7.8 (1.4) | 55.9 (4.9) | 48.2 (47.2 to 49.2) |
| Body weight (kg) | 4.9 (0.7) | 9.9 (1.2) | 5.0 (4.8 to 5.2) |
| Crown–heel length (cm) | 57.6 (2.5) | 77.6 (2.7) | 20.0 (19.5 to 20.5) |
| FRCpleth (ml) | 112 (26) | 249 (42) | 136 (129 to 144)1-152 |
| Rawii (kPa/l.s) | 4.11 (2.02) | 2.33 (1.30) | –1.85 (–2.30 to –1.39)1-153 |
| Rawee(kPa/l.s) | 4.57 (2.46) | 2.46 (1.35) | –2.24 (–2.73 to –1.76)1-153 |
| sGawii (/s/kPa) | 2.64 (1.02) | 2.09 (0.71) | –0.51 (–0.76 to –0.27)1-153 |
| sGawee (/s/kPa) | 2.41 (0.93) | 1.99 (0.71) | –0.36 (–0.57 to –0.16)1-153 |
| Crs (ml/kPa) | 65.6 (10.7) | 145.5 (20.9) | 80.4 (76.9 to 83.9)1-154 |
| sCrs (/kPa) | 0.61 (0.12) | 0.60 (0.10) | –0.01 (–0.04 to 0.02)1-160 |
| tptef:te | 0.324 (0.074) | 0.299 (0.079) | –0.024 (–0.040 to –0.008) |
| Respiratory rate (bpm) | 46 (9) | 30 (4) | –16 (–17 to –14) |
FRCpleth = functional residual capacity determined plethysmographically; Raw = airway resistance measured at initial inspiration (Rawii) or end expiration (Rawee); sGaw = specific conductance measured at initial inspiration (sGawii) or end expiration (sGawee); sCrs = specific respiratory compliance; tptef:te = time to peak tidal expiratory flow as a proportion of total expiratory time.
↵1-150 Data summarised as mean (SD).
↵1-151 95% CI = 95% confidence interval of difference in means for 100 infants unless otherwise stated.
↵1-152 n=99;
↵1-153 n=86;
↵1-154 n=92;
↵1-160 n=91.