Table 3—

Comparison of definitions by level of obstruction# in the older current and ex-smoker subgroup

LLN cut-offTotal
Moderate-to-very severe+Mild§Noneƒ
Fixed cut-off
 Moderate-to-very severe##15521005712223
  • LLN: lower limit of normal (i.e. sd score of <-1.645). #: based on post-bronchodilator forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) and FEV1; : 6,016 current or ex-smokers aged ≥50 yrs; +: FEV1/FVC<LLN and FEV1<LLN; §: FEV1/FVC<LLN and FEV1≥LLN; ƒ: FEV1/FVC≥LLN; ##: FEV1/FVC <0.70 and FEV1 <80% of predicted value; ¶¶: FEV1/FVC <0.70 and FEV1 ≥80% pred; ++: FEV1/FVC ≥0.70.