Previous studies on the association between smoking and rheumatoid arthritis
| Author | Year of publication | Study design, type of cases | Number of cases women/men | Relative risk with 95% confidence interval women/men/both sexes together | Examining separately the effect of duration, intensity |
|---|---|---|---|---|---|
| *NE, not examined; †relative risk with 95% confidence interval, calculated by us, based on results in this article; ‡MZ, monozygotic twin pairs discordant for rheumatoid arthritis; §DZ, dizygotic twin pairs discordant for rheumatoid arthritis. | |||||
| Vessey et al19 | 1987 | Cohort study, incident cases | 78/NE* | 2.4 (1.8 to 3.2)† / NE / NE | No, yes |
| Uhlig et al20 | 1999 | Case-control study, prevalent cases | 261/98 | 1.14 (0.80 to 1.62) / 2.38 (1.45 to 3.92) / 1.46 (1.10 to 1.94) | No, no |
| Karlsson et al21 | 1999 | Cohort study, prevalent cases | 7697/NE | 1.40 (1.28 to 1.53) / NE / NE | Yes, yes |
| Silman et al22 | 1996 | Matched twin pairs case-control study, prevalent cases | MZ‡ 65/14 | 10.0 (1.42 to 434) / NE / 12.0 (1.78 to 513) | Yes, no |
| DZ§ 55/16 | 2.4 (0.79 to 8.70) / 3.0 (0.24 to 158) / 2.5 (0.92 to 7.87) | ||||
| Hutchinsson et al23 | 2001 | Cases-control study, prevalent cases | 160/79 | NE / NE / 13.54 (2.89 to 63.28) | No, no |
| Reckner-Olsson et al24 | 2001 | Cases-control study, prevalent cases | 179/102 | 2.5 (0.9 to 6.7) / 3.4 (1.5 to 8.4) / NE | No, no |
| Voigt et al25 | 1994 | Case-control study, incident cases | 349/NE | 1.5 (1.0 to 2.0) / NE / NE | Yes, yes |
| Symmons et al26 | 1997 | Case-control study, incident cases | 115/50 | NE / NE / 1.66 (0.95 to 3.06) | No, no |
| Hazes et al27 | 1990 | Case-control study, incident cases | 135/NE | 0.61 (0.42 to 0.89) / NE / NE | No, yes |
| Heliövaara et al28 | 1993 | Cohort study, incident cases | 229/119 | 1.1 (0.8 to 1.6) / 4.4 (2.3 to 8.5) / NE | Yes, yes |
| Hernandez-Avila et al29 | 1990 | Cohort study, incident cases | 217/NE | 1.5 (0.9 to 2.3) / NE / NE | No, yes |
| Criswell et al30 | 2002 | Cohort study, incident cases | 158/NE | 2.0 (1.3 to 2.9) / NE / NE | Yes, yes |