Table 2

Demographic, anthropometric, lung function and clinical characteristics of patients at randomisation

CharacteristicsNPPV groupLTOT group
Subjects n3947
Sex M:F32:737:10
Age yrs64±766±14
Cigarette smoking pack-yrs29±626±5
FEV1 % pred.27±831±11
VC % pred.55±1762±15
RV % pred.193±78178±48
TLC % pred.118±29110±16
6MWD m200±125247±110
MIP cmH2O50±2046±21
Pa,CO2 kPa#7.2±0.67.4±0.6
Pa,O2 kPa#6.7±0.86.6±0.8
Hospital stays day·patient−1·yr−119±2018±18
SGRQ total score66±1462±21
LTOT months30±2229±23
  • Data are presented as mean±sd

  • NPPV: noninvasive positive-pressure ventilation and long-term oxygen therapy

  • LTOT: long-term oxygen therapy

  • M: male

  • F: female

  • BMI: body mass index

  • FEV1: forced expiratory volume in one second

  • VC: vital capacity

  • RV: residual volume

  • TLC: total lung capacity

  • 6MWD: 6-min walking distance test

  • MIP: maximal inspiratory pressure

  • Pa,CO2: carbon dioxide tension in arterial blood

  • Pa,O2: oxygen tension in arterial blood

  • SGRQ: St George's Respiratory Questionnaire

  • #: breathing room air

  • : year mean data for the 3 yrs before the study