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. Author manuscript; available in PMC: 2015 May 1.
Published in final edited form as: Thorax. 2013 Sep 12;69(5):492–495. doi: 10.1136/thoraxjnl-2013-203897

Table 1.

SPIROMICS Enrollment Strata

Non-Smokers (Stratum 1) Smokers (Stratum 2) Mild/Moderate COPD (Stratum 3) Severe COPD (Stratum 4)
Smoking Status < 1 pack-year > 20 pack-years > 20 pack-years > 20 pack-years
Bronchodilator Status for Assessing Lung Function Pre-bronchodilator Post-bronchodilator Post-bronchodilator Post-bronchodilator
FEV1/FVC ratio criteria FEV1/FVC > 0.7 FEV1/FVC > 0.7 FEV1/FVC < 0.7 FEV1/FVC < 0.7
Other Lung Function Criteria FVC>LLN FVC>LLN FEV1 > 50% pred. FEV1 < 50% pred.
Sample Size N = 200 (6.25%) N = 900 (28.1%) N = 1500 (46.9%) N = 600 (18.75%)

FEV1: forced expiratory volume in 1 second; FVC: forced vital capacity; LLN: lower limit of normal