Ever-, former-, current regular smoking and never-smoking at the time of pSS diagnosis date, stratified by HLA haplotype*
| HLA haplotype (present in cases and controls) | Exposure | Risk estimate | N exposed (%)¶ | ||
|---|---|---|---|---|---|
| OR | 95% CI | Cases | Controls | ||
| HLA-DRB1*03† | Ever-smoker | 0.60 | (0.40 to 0.92) | 55 (35) | 240 (47) |
| Former smoker | 0.72 | (0.46 to 1.13) | 43 (28) | 169 (33) | |
| Current smoker | 0.42 | (0.18 to 0.99) | 11 (7) | 71 (14) | |
| Never-smoker | Ref. | 89 (57) | 219 (43) | ||
| HLA-DRB1*15‡ | Ever-smoker | 0.87 | (0.57 to 1.31) | 58 (44) | 254 (46) |
| Former smoker | 0.97 | (0.62 to 1.51) | 45 (34) | 169 (31) | |
| Current smoker | 0.41 | (0.19 to 0.91) | 12 (9) | 85 (15) | |
| Never-smoker | Ref. | 68 (51) | 242 (44) | ||
| HLA-DRB1*01/04/10§ | Ever-smoker | 0.70 | (0.46 to 1.06) | 46 (39) | 376 (48) |
| Former smoker | 0.95 | (0.60 to 1.50) | 39 (33) | 244 (31) | |
| Current smoker | 0.27 | (0.11 to 0.66) | 6 (5) | 132 (17) | |
| Never-smoker | Ref. | 67 (56) | 339 (43) | ||
*Intermittent smoking was not included in exposure variables; never-smokers were defined as individuals reporting having never smoked regularly or intermittently.
†n=155 cases, n=515 controls.
‡n=133 cases, n=554 controls.
§n=119 cases, n=782 controls.
¶Sums of former and current smokers lower than number of ever-smokers relate to missing data/inconsistent reporting of respondents.
HLA, human leucocyte antigen; pSS, primary Sjögren’s syndrome; Ref., reference.