Variables | Prescription definition | Admission definition | ||

Hazard ratio (95% CI) | p-value | Hazard ratio (95% CI) | p-value | |

Factors related to exacerbation-free survival^{#} | ||||

BMI 1 kg·m^{−2} increase | 0.93 (0.87–0.99) | 0.03 | 0.86 (0.76–0.96) | 0.006 |

SGRQ total score 4 points increase | 1.12 (1.06–1.19) | <0.001 | 1.19 (1.08–1.30) | <0.001 |

Factor relating to exacerbation frequency^{¶} | ||||

BMI 1 kg·m^{−2} increase | 0.95 (0.90–0.99) | 0.03 | 0.87 (0.79–0.95) | 0.004 |

SGRQ total score 4 points increase | 1.09 (1.05–1.14) | <0.001 | 1.11 (1.03–1.20) | 0.008 |

FEV_{1} % predicted 10% increase | 0.89 (0.81–0.97) | 0.008 | ||

Haemoglobin 1 g·dL^{−1} increase | 0.84 (0.76–0.93) | 0.001 | ||

Factors related to recurrent exacerbation^{+} | ||||

Age 10-year increase | 1.57 (1.00–2.46) | 0.049 | ||

BMI 1 kg·m^{−2} increase | 0.88 (0.80–0.98) | 0.02 | ||

SGRQ total score 4 points increase | 1.07 (1.03–1.11) | <0.001 | 1.14 (1.04–1.24) | 0.005 |

Haemoglobin 1 g·dL^{−1} increase | 0.87 (0.78–0.97) | 0.02 |

Complete data tables including all variables and univariate analyses are shown in the online supplementary material. BMI: body mass index; SGRQ: St George’s Respiratory Questionnaire; FEV

_{1}: forced expiratory volume in 1 s.^{#}: Cox proportional hazards model;^{¶}: Poisson regression model;^{+}: Prentice, Williams and Peterson total time model.