Table 2 Demographic and exposure information in pre-primary Sjögren's syndrome cases and controls
From: Cigarette smoking and the risk of primary Sjögren’s syndrome: a nested case control study
Cases (n = 63) | Controls (n = 252) | P value** | |
|---|---|---|---|
Female sex, n (%) | 58/63 (92) | 232/252 (92) | 1.00 |
Age at inclusion in the population survey, mean (IQR), years | 52.6 (49.0–56.0) | 52.7 (49.0–56.0) | 0.94 |
Current smoker, n (%a) | 10/60 (17) | 92/251 (37) | 0.003 |
Former smoker, n (%a) | 32/60 (53) | 63/251 (25) | < 0.001 |
Never smoker, n (%a) | 18/60 (30) | 96/251 (38) | 0.23 |
White-collar worker, n (%a) | 26/54 (48) | 131/236 (56) | 0.33 |
Blue-collar worker, n (%a) | 22/54 (41) | 89/236 (38) | 0.68 |
Other socioeconomic status, n (%a) | 6/54 (11) | 16/236 (7) | 0.28 |
Low level of formal education, n (%a) | 25/58 (43) | 99/243 (41) | 0.73 |
Medium/high level of formal education, n (%a) | 33/58 (57) | 144/243 (59) | 0.73 |