IPFT | IPFT indices | Unit | Children with any viral ARI during infancy (n=154), median (IQR) | Children without ARI during infancy (n=52), median (IQR) | P-value |

TBFVL | V_{T}/kg | mL/kg | 11.3 (9.7–13.6) | 11.6 (10.2–13.8) | 0.8 |

TEF_{10} | mL/s | 123 (99–151) | 107 (82–139) | 0.02 | |

TEF_{25} | mL/s | 155 (126–186) | 135 (11–173) | 0.02 | |

MTEF | mL/s | 131 (108–158) | 120 (98–138) | 0.04 | |

TEF_{25}/PTEF | % | 79.7 (72.1–85.8) | 76.1 (68.4–83.4) | 0.03 | |

TEF_{50}/PTEF | % | 89.6 (86–93) | 87.3 (89.2) | 0.02 | |

RTC | Vʹ_{max,FRC} | mL/s | 60 (0–105) | 50 (0–95) | 0.7 |

RVRTC | FEV_{0.5} | mL | 58.2 (41–79.8) | 68 (45.3–101.8) | 0.03 |

FEV_{0.75} | mL | 79.5 (55.6–105.8) | 89.9 (69.6–125.1) | 0.03 | |

FEV_{1.0} | mL | 98.6 (73.4–124.8) | 112.2 (77.3–139.7) | 0.04 | |

FEV | mL | 119.8 (85.6–144.3) | 137.1 (117.9–164.5) | 0.006 | |

FEF_{25–75} | mL/s | 154.7 (102.3–212.1) | 212.5 (123.2–301.9) | 0.01 | |

MEF_{25} | mL/s | 125 (90–180) | 177.5 (100–310) | 0.008 | |

MEF_{10} | mL/s | 80 (60–130) | 130 (70–260) | 0.004 |

FEF

_{25-75}, forced expiratory flow between 25% and 75% of FVC; FEV_{0.5}/_{0.75}/_{1.0}, forced expiratory volume in 0.5/0.75/1 sec; FEV, forced expiratory volume; IPFT, infants pulmonary function test; MEF_{25}/MEF_{10}, maximum expiratory flow at 25% or 10% of FVC; MTEF, mid tidal expiratory flow; RTC, rapid thoracoabdominal compression; RVRTC, raised volume rapid thoracoabdominal compression; TBFVL, tidal breathing flow-volume loop; TEF_{25}or TEF_{10}, tidal expiratory flow when 25 % or 10 % of*V*_{T}remaining for expiration; TEF_{25}or TEF_{50}/PTEF, ratio of TEF_{25}or TEF_{50}to peaked tidal expiratory flow; Vʹ_{max,FRC}, maximal flow at FRC; VT, tidal volume.