Table 4. Mean spirometry, urine cotinine, and percent emphysema values, stratified by gender.

Variable	Male (N = 1048)	Female(N = 921)
FEV1 (mL)	2893.7+/−656.6	2025.2+/−490.1
FVC (mL)	3906.6+/−822.7	2641.6+/−613.1
FEV1/FVC Ratio	0.7+/−0.1	0.8+/−0.1
Calculated mean cotinine concentration (ng/ml)	725.6+/−2731.9	436.0+/−1943.8
Emphysema (%)	21.4+/−12.3	12.8+/−9.9