Table 2

Generalised linear models comparing adjusted effect size of smoking variables on outcomes

OutcomePredictorStandardised b SE of standardised b Z valueP value
FEV1/FVCDuration−0.3100.012
Cigarettes/day−0.0800.009−15.442<0.001
Pack-years−0.1830.009−8.353<0.001
FEV1 Duration−0.2530.011
Cigarettes/day−0.0770.008−12.853<0.001
Pack-years−0.1650.009−6.32<0.001
CT emphysemaDuration0.2190.012
Cigarettes/day0.0580.00910.385<0.001
Pack-years0.1280.0105.754<0.001
CT gas trappingDuration0.2470.012
Cigarettes/day0.0770.00911.009<0.001
Pack-years0.1590.0105.566<0.001
6MWDDuration−0.1860.012
Cigarettes/day−0.0820.009−7.055<0.001
Pack-years−0.1500.009−2.3870.008
SGRQDuration0.2270.013
Cigarettes/day0.1480.0104.907<0.001
Pack-years0.2300.0100.0420.483
  • Estimated standardised regression coefficient b is adjusted for age, race, sex, body mass index, scanner type, centre, age of smoking onset and current smoking status.

  • P value obtained by Z-test for comparing standardised b of smoking duration with that of cigarettes/day and pack-years of smoking.

  • 6MWD, 6 min walk distance; SGRQ, St George’s Respiratory Questionnaire.