Table 2.
Smoking characteristics of GenES study SLE patients and controls
| Patients (n = 258) | Controls (n = 263) | OR (95% CI)a | |
|---|---|---|---|
| n (%) | n (%) | ||
| Smoking Status | |||
| Never smoked | 169 (66) | 164 (62) | 1.0 (referent) |
| Ever smoked | 89 (35) | 99 (38) | 0.92 (0.64, 1.3) |
| Former smoker | 26 (10) | 23 (9) | 1.2 (0.67, 2.3) |
| Current smoker | 63 (24) | 76 (29) | 0.83 (0.55, 1.2) |
| Age began smoking, mean (s.d.), years | 15.6 (3.2) | 16.1 (3.3) | (0.30) |
| <16 | 50 (56) | 44 (44) | 1.2 (0.74, 1.9) |
| ≥16 | 39 (44) | 55 (56) | 0.71 (0.44, 1.2) |
| Cigarettes per day, mean (s.d.) | 12.4 (9.7) | 13.0 (7.9) | (0.62) |
| 1–9 | 38 (43) | 27 (27) | 1.4 (0.81, 2.4) |
| 10–19 | 28 (33) | 44 (44) | 0.66 (0.39, 1.1) |
| ≥20 | 22 (25) | 28 (28) | 0.85 (0.46, 1.6) |
aAdjusted for current age (continuous), sex and area (Ontario, Quebec, other provinces); the never smoked category is the referent group for analysis of age smoking began and amount smoked.