Table 4

Baseline IPFT indices in enrolled children

IPFTIPFT indicesUnitEnrolled children
(n=225),
median (IQR)
Children who had ARI episode during infancy
(n=173),
median (IQR)
Children who did not have ARI episode during infancy
(n=52),
median (IQR)
P value*
TBFVLVTmL7 (6 – 9)7 (6–9)7 (6–9)0.5
VT/kgmL/kg2.7 (2.1–3.1)2.7 (2.2–3.0)2.7 (2.1–3.2)0.5
tE/ttot%52.5 (50–55.6)52.5 (49.7–55)53 (50–56.5)0.2
tPTEF/tE%36.6 (30.9–44.3)36.5 (32.3–44.5)34.7 (25–39.6)0.007
TEF10mL/s13 (11–16)13 (11–16)12.5 (10–16)0.3
TEF25mL/s17 (13–20)17 (14–20)16 (12.5–19)0.5
TEF50mL/s20 (17–24)19 (17–24)21 (17–24)0.5
MTEFmL/s14 (12–17)14 (12–17)14 (11–17)0.9
TEF10/PTEF%59.1 (51.2–65.7)59.1 (53.1–66.2)54.8 (47.7–62.5)0.008
TEF25/PTEF%72.6 (66.3–78.7)73.1 (67.9–79.2)70.3 (64.8–76.7)0.008
TEF50/PTEF%89.2 (85.1–92.6)89 (85.2–92.2)90.4 (85.2–93.0)0.4
VPTEF/VE%37.5 (33.4–44.5)37.5 (33.3–44.4)33.3 (31.6–45.4)0.02
RTCmax,FRCmL/s45 (0–70)45 (0–70)60 (30–85)0.2
RVRTCFEV0.5mL45.7 (35.7–82.4)47.2 (39.8–74.8)43.8 (19.3–43.8)0.4
FEV0.75mL55.5 (43.8–62.3)56.8 (46.2–65.4)48.9 (31.8–61.5)0.3
FEV1.0mL68.1 (51–82.9)74.8 (56.2–81.7)61.4 (44.3–84.2)0.6
FEVmL63.9 (53.4–81.4)62.3 (53.4–81.4)65.5 (46.6–86.8)0.5
MEF25mL/s65 (45–110)65 (50–100)45 (40–75)0.2
MEF10mL/s40 (35–65)40 (35–65)35 (30–60)0.2
FEF25–75mL/s80.8 (51–134.2)80.8 (52.5–107)56.2 (44.3–97.5)0.3
PEFmL/s200 (145–265)205 (150–340)175 (100–220)0.1
  • *Comparison is between children who had ARI during infancy and those who did not have any ARI episode in infancy.

  • ARI, acute respiratory infection; FEF25–75, forced expiratory flow between 25% and 75% of FVC; FEV, forced expiratory volume; FEV0.5, FEV0.75, FEV1.0, forced expiratory volume in 0.5/0.75/1 s; IPFT, infant pulmonary function test; MEF25/MEF10, maximum expiratory flow at 25% or 10% of FVC; MTEF, mid tidal expiratory flow; PEF, peak expiratory flow; PTEF, peak tidal expiratory flow; RTC, rapid thoracoabdominal compression; RVRTC, raised volume rapid thoracoabdominal compression; TBFVL, tidal breathing flow-volume loop; TEF10 or TEF25 or TEF 50/PTEF, the ratio of TEF10, TEF25 or TEF50 to peaked tidal expiratory flow; TEF10/TEF25/TEF50, tidal expiratory flow when 10%/25%/50% of tidal volume remaining for expiration; tE/ttot, ratio of expiratory time to total respiratory time; tPTEF/tE, the ratio of time to peak tidal expiratory flow to total expiratory time; Vʹmax, FRC, maximal flow at functional residual capacity; VPTEF/VE, ratio of exhaled volume to PTEF to tidal expiratory volume; VT, tidal volume; VT/kg, tidal volume per unit bodyweight.