Table 2

Respiratory-related variables, by cohort

1996–72003–4p Value
FEV1 ml±SD989±3761054±3750.14
FEV1% predicted±SD41.4±13.045.1±14.40.02
Pao2 on admission±SD59.9±17.862.7±20.40.2
Paco2 on admission ±SD44.8±12.642.3±13.90.2
Pao2 at discharge ±SD70±1563±100.009
Paco2 at discharge41±842±90.2
Dyspnoea by mMRC±SD2.4±1.32.8±1.20.03
Cor pulmonale (%)44 (32.6%)60 (33.5%)0.5
Chronic oxygen therapy (%)23 (17.4%)32 (17.9%)0.5
  • As described in the Methods section, spirometry was conducted at discharge in 1996–7, and at baseline in 2003–4.

  • FEV1, forced expiratory volume in 1 s; mMRC, modified Medical Research Council scale.