Table 1 Characteristics of studies on rheumatoid arthritis and pack-years
From: Cigarette smoking and risk of rheumatoid arthritis: a dose-response meta-analysis
Authors, year | Study population, country, follow-up period/study period | Cases/cohort size or controls | Range of exposure pack-years | Highest category | RR/OR* Highest vs. lowest category§(95% CI) | Controlled variables | NOQAS* |
|---|---|---|---|---|---|---|---|
Cohort | |||||||
Criswell et al., 2002 [20] | Iowa Women’s Health Study, USA, 1986 to 1997 | Women 158/31,336 | 0 to 50a | ≥40 | Total 1.7 (1.0 to 3.0) | Age, body mass index, alcohol use, coffee consumption, marital status, occupation, age at menopause, use of oral contraceptives and hormone replacement therapy. | 8 |
Costenbader et al., 2006 [4] | Nurses’ Health Study, USA, 1976 to 2002 | Women 680/103,818 | 0 to 45a | >40 | Total 1.86 (1.46 to 2.38) RF +* 2.22 (1.63 to 3.02) RF-* 1.43 (0.96 to 2.12) | Age, body mass index, alcohol intake, father’s occupation, age at menarche, menstrual regularity, duration of breastfeeding, postmenopausal hormone use. | 8 |
Di Giuseppe et al., 2013 [5] | Swedish mammography cohort, 2003 to 2010 | Women 219/34,101 | 0 to 28b | >22 | Total 1.82 (1.19 to 2.79) | Age, menopause status, parity, alcohol use, educational level, and body mass index. | 8 |
Case-control | |||||||
Voigt et al., 1994 [16] | Population-based controls, USA, 1986 to 1991 | Women 349/1,457 | 0-27a | >20 | Total 1.49 (1.06 to 2.10) | Age, body mass index. | 7 |
Hutchinson et al., 2001 [24] | Hospital-based controls, UK | Men + Women 239/239 | 0 to 55a | >50 | Total 8.41 (2.45 to 28.84) | Matched for age, gender and social class. | 7 |
Olsson et al., 2001 [21] | Population-based controls, Sweden, 1980 to 1995 | Men 91/203 Women 154/222 | 0 to 27a | ≥20 | Total men 2.7 (1.2 to 5.8) Total Women 1.8 (0.7 to 4.6) RF + Men 3.4 (1.5 to 8.4) RF + Women 2.5 (0.9 to 6.7) | Age, economic status. | 7 |
Stolt et al., 2003 [2] | Population-based controls, Sweden, 1996 to 2000 | Men + Women 486/724 | 0 to 25a | ≥20 | RF + 2.7 (1.8 to 3..9) | Age, residential area and gender. | 7 |
Pedersen et al., 2006 [22] | Population-based controls, Denmark, 1988 to 2003 | Men 149/291 Women 366/478 | 0 to 25a | >20 | Total men 2.00 (1.12 to 3.58) Total Women 2.07 (1.35 to 3.16) | Birth year, year of RA diagnosis, gender. | 7 |
Mikuls et al., 2010 [14] | Population-based controls, US (African Americans) | Men + Women 605/255 | 0 to 15a | ≥10 | Total 2.37 (1.56 to 3.60) RF + 2.51 (1.63 to 3.87) RF- 1.93 (1.11 to 3.35) | Age, gender. | 7 |
Yahya et al., 2012 [23] | Population-based controls, Malaysia, 2005 to 2009 | Men + Women 1056/1416 | 0 to 25a | ≥20 | Total 2.3 (1.0 to 5.5) | Matched for age, gender and residential area. Additionally adjusted for formal education and ethnicity. | 6 |