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. Author manuscript; available in PMC: 2017 Mar 1.
Published in final edited form as: Contemp Clin Trials. 2016 Jan 16;47:185–195. doi: 10.1016/j.cct.2016.01.003

Table 5.

Questionnaire report of COPD and asthma diagnosis by spirometry grade for 1924 subjects with acceptable spirometry.

Spirometry Grade Definition by pulmonary function N (1) % Percent of (1) with COPD dx Percent of (1) with COPD dx or asthma dx
NO COPD FEV1/FVC ≥ 0.70 1285 66.8% 6.8% 18.3%
PRISm FEV1 < 80% normal 113 5.9% 7.1% 23.9%
I Mild FEV1/FVC < 0.70 and FEV1 ≥ 80% normal 329 17.1% 8.9% 28.1%
II Moderate FEV1/FVC < 0.70 and FEV1 50–79% normal 172 8.9% 30.2% 55.8%
III Severe FEV1/FVC < 0.70 and FEV1 30–49% normal 22 1.1% 50.0% 63.6%
IV Very Severe FEV1/FVC < 0.70 and FEV1 <30% normal 3 0.2% 100% 100%
1924 100% N=1905 N=1919