Table 1 Characteristics of studies on rheumatoid arthritis and fish consumption

Cohort

Pedersen et al., 2005 [12]

Diet, Cancer and Health cohort, Denmark, 1993 to 2001

69/56 691

Men and women, 50 to 64

Per 30 g/day: 0.91 (0.68, 1.23)

Age and gender

6

Benito-Garcia, 2007 [11]

Nurses' Health Study, USA, 1980 to 2002

546/82 063

Women, 30 to 55

Q1 (median 0.07 s/d¹): 1.00 (ref)

Age, total energy intake, body mass index, smoking, total lifetime breastfeeding

7

Q2 (0.13 s/d): 0.94 (0.73, 1.23)

Q3 (0.17 s/d): 1.09 (0.81, 1.47)

Q4 (0.25 s/d): 1.06 (0.80, 1.40)

Q5 (0.44 s/d): 0.96 (0.72, 1.26)

Di Giuseppe et al., 2013 [7]

Swedish Mammography Cohort, 2003 to 2010

205/32 232

Women, 54 to 89

<1 s/w¹ nel 1987, <1 s/w nel 1997:

Age, cigarette smoking, alcohol intake, use of aspirin, red meat consumption, dairy food consumption, energy intake

8

1.00 (ref)

≥1 s/w nel 1987, <1 s/w nel 1997:

0.78 (0.50, 1.22)

<1 s/w nel 1987, ≥1 s/w nel 1997:

1.01 (0.66, 1.56)

≥1 s/w nel 1987, ≥1 s/w nel 1997:

0.71 (0.48, 1.04)

Case-control

Linos et al., 1991 [9]

Hospital-based controls, Greece

168/137

Men and women, 24 to 89

1-2 s/m¹: 1.00 (ref)

Age and gender

5

4-10 s/m: 0.64 (0.38, 1.08)

12+ s/m: 0.37 (0.13, 1.05)

Shapiro et al., 1996 [14]

Population-based controls, USA, 1986 to 1991

324/1245

Women, 18 to 64

<1 s/w: 1.00 (ref)

Reference age, reference year, education, race, total caloric intake

8

1- <2 s/w: 0.87

(0.62, 1.21)

≥2 s/w: 0.92 (0.67, 1.25)

Linos et al., 1999 [13]

Hospital-based controls, Greece

145/188

Men and women, 18 to 84

Q1 (median 3 s/w): 1.00 (ref)

Age and gender

5

Q2 (4 s/w): 1.21 (0.64, 2.29)

Q3 (6 s/w): 0.90 (0.47, -1.71)

Q4 (10 s/w): 0.95 (0.46, 1.96)

Rosell et al., 2009 [10]

Population-based controls (EIRA), Sweden, 1996 to 2005

1889/2145

Men and women, 18 to 70

Never/seldom: 1.00 (ref)

Age, residential area, smoking, gender

6

1-3 s/m: 0.8 (0.7, 1.0)

1-7 s/w: 0.8 (0.6, 1.0)