Parameter | First 3-yr period | Second 3-yr period | ||||

Exposed period | Not exposed period | p-value^{#} | Not exposed period | Exposed period | p-value^{#} | |

Δ FEV_{1} % pred | -0.40 (-22.4–7.55)^{¶} | -2.00 (-16.70–4.85)^{¶} | 0.265 | -1.83 (-15.50–6.60)^{§} | -2.35 (-9.30–6.65)^{§} | 0.426 |

ΔBMI kg·m^{−2} | -0.02 (-0.64–1.64)^{¶} | -0.02 (-1.4–1.54)^{¶} | 0.316 | -0.01 (-1.62–1.30)^{ƒ} | -0.27 (-1.87–1.38)^{ƒ} | 0.618 |

Total i.v. antibiotics days | 28 (0–84)^{+} | 28 (0–168)^{+} | 0.567 | 42 (0–140)^{§} | 56 (0–238)^{§} | 0.725 |

Data are presented as median (range), unless otherwise stated. Females with 3 yrs of OC use (exposed period) followed by 3 yrs of no OC use (not exposed period) or 3 yrs of no OC use (not exposed period) followed by 3 yrs of OC use (exposed period) were included in the analysis. Annual change (Δ) in % predicted forced expiratory volume in 1 s (FEV

_{1}% pred), annual change in body mass index (BMI) and total number of days of intravenous antibiotics were compared for each 3-yr study period.^{#}: p-values indicate comparison between values for age of females;^{¶}: n=27;^{+}: n=25;^{§}: n=23;^{ƒ}: n=24.