FVC ≥ 70 (Total Number = 337)

Pass

Fail

NHANES III (1999)

328 (97.32%)

9 (2.67%)

Crapo et al. 1981

325 (96.43%)

12 (3.5%)

Knudson et al. 1983

330 (97.92%)

7 (2.07%)