FEV1 ≥ 70 (Total Number = 337)

Pass

Fail

NHANES III (1999)

323 (95.84%)

14 (4.15%)

Crapo et al. 1981

318 (94.36%)

19 (5.63%)

Knudson et al. 1983

322 (95.54%)

15 (4.45%)