Table 1

Summary of selected studies

Authors, year (ref no)GenderRR or OR (95% CI)AdjustmentSmoking rate (%)
Ever smokersCurrent smokersPast smokersCases/controls or cohort sizeEver smokersCurrent smokersPast smokersStudy designStudy qualityStudy area
Vessey et al, 19875Female1.50 (0.93 to 2.44)1.66 (1.00 to 2.78)1.15 (0.54 to 2.43)(No)78/60047.533.813.6Cohort5Europe
Hazes et al, 199034Female0.61 (0.42 to 0.89)Year of birth, age at onset of symtoms,135/37843.9
parity, alcohol consumption, oral cotraceptive,Case–control10Europe
marital status, menopause
Heliovaara et al, 200038Both512/52 80947.635.612.1
RF+ cases1.85 (1.26 to 2.70)1.93 (1.14 to 3.28)1.76 (0.92 to 3.38)Consumption of coffee, age, BMI, serum cholesterol, sex,
level of education, smoking, intake of alcohol
Heliovaara et al, 19937Male2.04 (1.10 to 3.79)1.60 (0.70 to 3.80)1.40 (0.50 to 3.80)Age161/28 36469.751.118.7
RF+ cases3.86 (2.71 to 5.49)4.31 (2.87 to 6.50)2.80 (1.40 to 5.60)Cohort13Europe
RF− cases0.81 (0.49 to 1.34)0.66 (0.34 to 1.27)1.10 (0.50 to 2.40)
Female1.06 (0.84 to 1.35)1.10 (0.84 to 1.44)0.92 (0.53 to 1.58)Age351/24 44522.117.74.5
RF+ cases1.04 (0.78 to 1.40)1.10 (0.80 to 1.52)0.80 (0.40 to 1.70)
RF− cases1.10 (0.73 to 1.66)1.10 (0.70 to 1.80)1.10 (0.50 to 2.60)
Voigt et al, 19948Female1.31 (1.07 to 1.60)1.33 (1.00 to 1.77)1.28 (0.96 to 1.71)Age, BMI349/145750.926.024.9Case–control10USA
PY <201.49 (1.06 to 2.10)
PY >201.16 (0.90 to 1.50)
Symmons et al, 19979Both1.66 (0.95 to 3.06)0.95 (0.56 to 1.61)Sex,social class90/9354.5
RF+ cases2.92 (0.92 to 9.21)Case–control12Europe
RF− cases1.20 (0.70 to 2.09)
Uhlig et al, 199911Both1.46 (1.10 to 1.94)Age, sex, education, marital status, employment, BMI361/546932.9
Male2.38 (1.45 to 3.92)Age,education, marital status, employment, BMI99/262633.4
RF+ cases4.77 (2.09 to 10.90)
RF− cases1.57 (0.80 to 3.06)Case–control13Europe
Female1.14 (0.8 to 1.62)Age, education, marital status, employment, BMI262/284332.2
RF+ cases0.67 (0.37 to 1.20)
RF− cases1.54 (0.99 to 2.39)
Karlson et al, 199910Female1.13 (1.08 to 1.18)1.18 (1.07 to 1.31)1.06 (0.96 to 1.13)Age, race, education, age at menarche, pregnancy history,7697/37 748145.213.232.0Cohort13USA
menopausal status, postmenopausal HRT
Hutchinson et al, 200112Both1.81 (1.22 to 2.19)(Not clearly shown)239/23958.331.826.6.Case–control10Europe
Olsson et al, 200119Male1.97 (1.18 to 3.29)2.20 (1.10 to 4.20)Age, socioeconomic status91/20365.6
RF+ cases2.42 (1.36 to 4.32)
PY <201.39 (0.56 to 3.44)
PY >202.70 (1.20 to 5.80)Case–control12Europe
female1.61 (1.06 to 2.45)Age, socioeconomic status154/22238.0
RF+ cases1.94 (1.24 to 3.01)
PY <201.57 (0.99 to 2.50)
PY >201.80 (0.70 to 4.60)
Criswell et al, 200239Female1.70 (1.02 to 2.85)2.20 (1.40 to 3.30)1.30 (0.80 to 2.00)Age, alcohol use, coffee consumption, marital status,154/31 33633.013.417.1Cohort13USA
PY <201.10 (0.60 to 1.80)BMI, age at menopause, oral contraceptives, HRT
PY >201.99 (1.41 to 2.81)
Krishnan et al, 200331Male1.56 (0.95 to 2.58)1.20 (0.70 to 2.00)2.00 (1.20 to 3.20)Age, BMI, education, HAQ index,318/42676.519.756.8
RF+ cases1.88 (1.24 to 2.86)1.50 (0.80 to 2.60)2.30 (1.30 to 3.90)general health assessment, pain
RF− cases1.16 (0.63 to 2.22)0.80 (0.30 to 1.80)0.90 (0.40 to 1.90)Case–control12Europe
female0.81 (0.60 to 1.09)0.70 (0.40 to 1.00)0.90 (0.60 to 1.30)Age, BMI, education, HAQ index,777/110430.611.119.5
RF+ cases0.74 (0.53 to 1.02)0.60 (0.30 to 1.00)0.80 (0.60 to 1.30)general health assessment, pain
RF− cases0.90 (0.63 to 1.28)0.84 (0.50 to 1.50)0.94 (0.60 to 1.50)
Krishnan, 200335Both1.34 (1.00 to 1.81)1.42 (1.13 to 1.80)1.08 (0.87 to 1.34)No644/150949.520.928.9
Male2.29 (1.35 to 3.90)Age, race, education, income, living alone203/54368.3Case–control10USA
Female0.98 (0.67 to 1.42)Age, race, education, income, living alone441/94639.2
Stolt et al, 200320Male1.40 (0.80 to 2.30)1.30 (0.70 to 2.40)1.40 (0.80 to 2.50)Age, residential area190/24574.737.037.7
RF+ cases1.90 (1.00 to 3.50)1.80 (0.80 to 4.10)1.90 (0.90 to 3.80)
RF− cases0.80 (0.40 to 1.60)0.70 (0.30 to 1.60)0.90 (0.40 to 1.90)Case–control13Europe
Female1.30 (1.00 to 1.70)1.40 (1.00 to 2.00)1.20 (0.90 to 1.70)Age, residential area489/60264.433.619.1
RF+ cases1.70 (1.20 to 2.30)1.80 (1.30 to 2.60)1.60 (1.10 to 2.30)
RF− cases0.80 (0.60 to 1.20)0.90 (0.50 to 1.40)0.80 (0.50 to 1.30)
Padyukov et al, 200422Both1.50 (1.20 to 2.00)Age(10 strata), sex, residential area858/104823.6
RF+ cases2.20 (1.70 to 3.00)
RF− cases0.80 (0.60 to 2.20)
Male1.70 (1.00 to 2.90)Age(10 strata), residential area246/31219.7
RF+ cases3.30 (1.70 to 6.30)Case–control13Europe
RF− cases0.60 (0.30 to 1.30)
Female1.50 (1.10 to 2.00)Age(10 strata), residential area612/73625.5
RF+ cases2.20 (1.60 to 3.00)
RF− cases0.80 (0.60 to 1.30)
Olsson et al, 200421Male2.54 (1.55 to 4.16)2.90 (1.40 to 6.40)2.30 (1.20 to 4.40)Age74/38263.822.244.3Case–control11Europe
RF+ cases4.60 (2.20 to 9.60)5.80 (1.90 to 17.10)3.80 (1.40 to 10.20)
PY <202.20 (1.15 to 4.22)
PY >202.50 (1.20 to 5.10)
Female1.52 (1.09 to 2.12)1.80 (1.10 to 2.90)1.30 (0.80 to 2.00)Age159/36852.819.730.8Case–control11Europe
RF+ cases1.56 (1.03 to 2.36)1.80 (1.00 to 3.50)1.40 (0.80 to 2.40)
PY <201.33 (0.86 to 2.04)
PY >201.60 (0.90 to 3.10)
Costenbader et al, 200637Female1.46 (1.24 to 1.71)1.43 (1.16 to 1.75)1.47 (1.24 to 1.71)BMI, alcohol intake, father’s occupation,680/103 81855.517.538.1
RF+ cases1.59 (1.29 to 1.97)1.58 (1.21 to 2.06)1.60 (1.27 to 2.02)age at menarche, regularity of menses,Cohort14USA
RF− cases1.28 (1.00 to 1.65)1.23 (0.88 to 1.70)1.31 (1.00 to 1.73)duration of breastfeeding, postmenopausal HRT
PY <201.19 (0.95 to 1.50)
PY >201.72 (1.41 to 2.11)
Pedersen et al, 200636Both1.70 (1.38 to 2.10)1.80 (1.37 to 2.36)1.57 (1.13 to 2.19)Birth year, year of diagnosis
CCP+ cases1.66 (1.23 to 2.24)1.73 (1.17 to 2.56)1.57 (0.99 to 2.48)Sex,birth year, year of diagnosis,residence area,
history of urinary tract infection, maritul status,515/76964.744.228.9
CCP− cases1.04 (0.65 to 1.68)0.83 (0.49 to 1.39)1.35 (0.76 to 2.39)coffee consumption, alcohol consumption, BMI
Physical activity, pets as adult, asthma,
schizophrenia among 1st degree relatives
Male1.75 (1.15 to 2.65)1.89 (1.09 to 3.30)1.58 (0.84 to 2.97)Birth year, year of diagnosis149/29177.050.027.0Case–control12Europe
PY <201.63 (0.99 to 2.70)
PY >202.00 (1.12 to 3.58)
Female1.78 (1.38 to 2.97)1.84 (1.33 to 2.54)1.69 (1.12 to 2.55)Birth year, year of diagnosis366/47858.441.430.0
PY <201.68 (1.27 to 2.26)
PY >202.07 (1.35 to 3.16)
  • BMI, body mass index; CCP, citrulline protein/peptide; HRT, hormone replacement therapy; OR, odds ratio; PY, pack-years smoked; RF, rheumatoid factor; RR, relative risk.