Ratio of Forced Expiratory Volume in 1 second /Slow Vital Capacity (FEV1/SVC)<0.7 is associated with clinical, functional, and radiologic features of obstructive lung disease in smokers with preserved lung function.

Fortis S, Comellas A, Bhatt SP, Hoffman EA, Han MK, Bhakta NR, Paine R, Ronish B, Kanner RE, Dransfield M, Hoesterey D, Buhr RG, Barr RG, Dolezal B, Ortega VE, Drummond MB, Arjomandi M, Kaner RJ, Kim V, Curtis JL, Bowler RP, Martinez F, Labaki WW, Cooper CB, O'Neal WK, Criner G, Hansel NN, Krishnan JA, Woodruff P, Couper D, Tashkin D, Barjaktarevic I