Table 2 Subgroup analysis for the effect of omega–3 fatty acid supplementation on cancer incidence, nonvascular death, and total mortality

Publication year

Before 2000

5

1.07 (0.85–1.34)

0.56

0

0.87

0.789

After 2000

6

1.11 (0.96–1.28)

0.15

0

0.93

Number of patients

>1000

5

1.10 (0.97–1.24)

0.12

0

0.98

0.878

<1000

6

1.03 (0.45–2.38)

0.94

0

0.83

Percent men (%)

>80

7

1.06 (0.87–1.28)

0.58

0

0.98

0.608

<80

4

1.13 (0.97–1.31)

0.13

0

0.72

Mean age

>64

1

5.00 (0.24–103.28)

0.30

–

–

0.328

<64

10

1.10 (0.97–1.24)

0.13

0

1.00

Intervention

Alpha–linolenic acid

1

0.33 (0.01–8.09)

0.50

–

–

0.481

Long–chain n–3 PUFA

10

1.10 (0.98–1.24)

0.12

0

0.99

Primary or secondary prevention

Primary

1

1.11 (0.93–1.33)

0.26

–

–

0.882

Secondary

10

1.09 (0.93–1.28)

0.29

0

0.98

Duration of the follow–up period (months)

>36

4

1.10 (0.97–1.24)

0.14

0

0.98

0.883

<36

7

1.16 (0.58–2.33)

0.68

0

0.88

Jadad score

>4

6

1.11 (0.96–1.30)

0.16

0

0.98

0.771

<4

5

1.07 (0.88–1.30)

0.49

0

0.77

Publication year

Before 2000

5

0.93 (0.77–1.13)

0.47

0

0.82

0.440

After 2000

11

1.01 (0.93–1.10)

0.75

0

0.86

Number of patients

>1000

8

1.01 (0.93–1.09)

0.89

0

0.89

0.328

<1000

8

0.77 (0.45–1.32)

0.34

0

0.80

Percent men (%)

>80

9

0.93 (0.80–1.08)

0.37

0

0.78

0.219

<80

6

1.04 (0.94–1.14)

0.47

0

0.92

Mean age

>64

7

1.01 (0.86–1.19)

0.89

0

0.83

0.916

<64

9

1.00 (0.91–1.09)

0.94

0

0.78

Intervention

Alpha–linolenic acid

3

0.95 (0.32–2.85)

0.93

0

0.54

0.927

Long–chain n–3 PUFA

13

1.00 (0.93–1.08)

1.00

0

0.89

Primary or secondary prevention

Primary

3

1.01 (0.87–1.18)

0.87

31.6

0.23

0.754

Secondary

13

0.98 (0.88–1.10)

0.78

0

0.97

Duration of the follow–up period (months)

>36

7

0.99 (0.92–1.08)

0.85

0

0.68

0.460

<36

9

1.11 (0.83–1.49)

0.49

0

0.92

Jadad score

>4

8

1.02 (0.93–1.11)

0.71

0

0.62

0.427

<4

8

0.95 (0.82–1.11)

0.54

0

0.97

Publication year

Before 2000

5

0.79 (0.67–0.93)

0.005

19

0.30

0.009

After 2000

12

1.00 (0.94–1.08)

0.90

29

0.16

Number of patients

>1000

9

0.98 (0.91–1.06)

0.57

57

0.02

0.014

<1000

8

0.67 (0.50–0.90)

0.007

0

0.59

Percent men (%)

>80

9

0.80 (0.65–0.98)

0.03

64

0.005

0.033

<80

7

1.01 (0.95–1.08)

0.71

0

0.84

Mean age

>64

7

0.96 (0.89–1.02)

0.20

0

0.44

0.543

<64

10

0.92 (0.82–1.04)

0.18

62

0.004

Intervention

Alpha–linolenic acid

3

0.58 (0.35–0.98)

0.04

0

0.46

0.058

Long–chain n–3 PUFA

14

0.96 (0.89–1.04)

0.36

47

0.03

Primary or secondary prevention

Primary

3

0.99 (0.86–1.14)

0.91

46

0.15

0.566

Secondary

14

0.94 (0.84–1.04)

0.21

47

0.03

Duration of the follow–up period (months)

>36

8

0.98 (0.91–1.05)

0.54

47

0.06

0.157

<36

9

0.80 (0.61–1.05)

0.11

43

0.08

Jadad score

>4

9

0.98 (0.91–1.06)

0.65

30

0.18

0.320

<4

8

0.88 (0.72–1.07)

0.19

59

0.02