IPFT | IPFT indices | Unit | Enrolled 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* |

TBFVL | V_{T} | mL | 7 (6 – 9) | 7 (6–9) | 7 (6–9) | 0.5 |

V_{T}/kg | mL/kg | 2.7 (2.1–3.1) | 2.7 (2.2–3.0) | 2.7 (2.1–3.2) | 0.5 | |

t_{E}/t_{tot} | % | 52.5 (50–55.6) | 52.5 (49.7–55) | 53 (50–56.5) | 0.2 | |

t_{PTEF}/t_{E} | % | 36.6 (30.9–44.3) | 36.5 (32.3–44.5) | 34.7 (25–39.6) | 0.007 | |

TEF_{10} | mL/s | 13 (11–16) | 13 (11–16) | 12.5 (10–16) | 0.3 | |

TEF_{25} | mL/s | 17 (13–20) | 17 (14–20) | 16 (12.5–19) | 0.5 | |

TEF_{50} | mL/s | 20 (17–24) | 19 (17–24) | 21 (17–24) | 0.5 | |

MTEF | mL/s | 14 (12–17) | 14 (12–17) | 14 (11–17) | 0.9 | |

TEF_{10}/PTEF | % | 59.1 (51.2–65.7) | 59.1 (53.1–66.2) | 54.8 (47.7–62.5) | 0.008 | |

TEF_{25}/PTEF | % | 72.6 (66.3–78.7) | 73.1 (67.9–79.2) | 70.3 (64.8–76.7) | 0.008 | |

TEF_{50}/PTEF | % | 89.2 (85.1–92.6) | 89 (85.2–92.2) | 90.4 (85.2–93.0) | 0.4 | |

V_{PTEF}/V_{E} | % | 37.5 (33.4–44.5) | 37.5 (33.3–44.4) | 33.3 (31.6–45.4) | 0.02 | |

RTC | Vʹ_{max,FRC} | mL/s | 45 (0–70) | 45 (0–70) | 60 (30–85) | 0.2 |

RVRTC | FEV_{0.5} | mL | 45.7 (35.7–82.4) | 47.2 (39.8–74.8) | 43.8 (19.3–43.8) | 0.4 |

FEV_{0.75} | mL | 55.5 (43.8–62.3) | 56.8 (46.2–65.4) | 48.9 (31.8–61.5) | 0.3 | |

FEV_{1.0} | mL | 68.1 (51–82.9) | 74.8 (56.2–81.7) | 61.4 (44.3–84.2) | 0.6 | |

FEV | mL | 63.9 (53.4–81.4) | 62.3 (53.4–81.4) | 65.5 (46.6–86.8) | 0.5 | |

MEF_{25} | mL/s | 65 (45–110) | 65 (50–100) | 45 (40–75) | 0.2 | |

MEF_{10} | mL/s | 40 (35–65) | 40 (35–65) | 35 (30–60) | 0.2 | |

FEF_{25–75} | mL/s | 80.8 (51–134.2) | 80.8 (52.5–107) | 56.2 (44.3–97.5) | 0.3 | |

PEF | mL/s | 200 (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; FEF

_{25–75}, forced expiratory flow between 25% and 75% of FVC; FEV, forced expiratory volume; FEV_{0.5}, FEV_{0.75}, FEV_{1.0}, forced expiratory volume in 0.5/0.75/1 s; IPFT, infant pulmonary function test; MEF_{25}/MEF_{10}, 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; TEF_{10}or TEF_{25}or TEF_{50}/PTEF, the ratio of TEF_{10}, TEF_{25}or TEF_{50}to peaked tidal expiratory flow; TEF_{10}/TEF_{25}/TEF_{50}, tidal expiratory flow when 10%/25%/50% of tidal volume remaining for expiration; t_{E}/t_{tot}, ratio of expiratory time to total respiratory time; t_{PTEF}/t_{E}, the ratio of time to peak tidal expiratory flow to total expiratory time; Vʹ_{max, FRC}, maximal flow at functional residual capacity; V_{PTEF}/V_{E}, ratio of exhaled volume to PTEF to tidal expiratory volume; V_{T}, tidal volume; VT/kg, tidal volume per unit bodyweight.