Older age at onset (OR 1.02), shorter time from onset to diagnosis (OR 0.96), smoking (OR 2.57), interstitial lung disease (ILD) (OR 1.58), less predisposition to sicca syndrome and to antinuclear antibody positivity (OR 0.29 and 0.43, respectively), and higher compliance with the ACR 1980 criteria (OR 1.79) were independently associated with the male sex.