Table 7 Main meta-analyses for current smoking of any product (or cigarettes, if any product not available)^a

All

All

N

120

113

22

F

3.00 (2.91-3.09)

2.82 (2.74-2.90)

2.61 (2.33-2.93)

R

3.51 (3.08-3.99)

3.41 (3.13-3.72)

4.87 (2.83-8.41)

H, P_H

13.81, < 0.001

5.80, < 0.001

11.54, < 0.001

Sex

Male

N

48

51

13

F

3.80 (3.60-4.02)

3.08 (2.90-3.28)

6.71 (5.29-8.53)

R

4.11 (3.28-5.15)

4.07 (3.44-4.83)

7.66 (3.00-19.61)

Female

n

31

37

5

F

2.53 (2.39-2.68)

2.75 (2.60-2.90)

2.85 (1.94-4.18)

R

3.28 (2.35-4.58)

3.23 (2.80-3.72)

2.85 (1.94-4.18)

Combined

n

41

25

4

F

2.81 (2.69-2.95)

2.74 (2.62-2.86)

1.86 (1.62-2.14)

R

3.04 (2.60-3.55)

2.98 (2.57-3.47)

2.54 (1.54-4.20)

Between levels

P_B

< 0.05

NS

< 0.05

Continent

N America

n

39

40

10

F

5.02 (4.76-5.29)

3.44 (3.20-3.69)

8.13 (6.32-10.45)

R

4.56 (3.69-5.62)

4.11 (3.41-4.97)

8.99 (3.34-24.26)

Europe

n

55

58

7

F

2.31 (2.22-2.41)

2.79 (2.69-2.89)

1.83 (1.58-2.11)

R

3.31 (2.80-3.92)

3.28 (2.96-3.62)

2.88 (1.36-6.09)

Asia

n

17

9

5

F

2.73 (2.45-3.05)

1.83 (1.65-2.02)

2.52 (1.83-3.47)

R

2.86 (2.27-3.60)

2.26 (1.67-3.05)

2.74 (1.50-4.99)

Other or multicountry

n

9

6

0

F

2.15 (1.89-2.44)

3.32 (2.94-3.75)

R

2.37 (1.75-3.21)

3.11 (2.33-4.16)

Between levels

P_B

< 0.001

< 0.001

< 0.01

Publication year

Before 1980

n

24

50

7

F

5.64 (5.12-6.21)

3.59 (3.36-3.84)

15.01 (10.59-21.28)

R

3.81 (2.64-5.50)

3.96 (3.41-4.59)

10.21 (2.09-49.96)

1980-89

n

11

26

6

F

2.18 (1.84-2.59)

2.29 (2.16-2.44)

1.83 (1.59-2.10)

R

2.47 (1.87-3.27)

3.25 (2.67-3.96)

1.83 (1.59-2.10)

1990-99

n

18

17

3

F

6.20 (5.59-6.88)

2.74 (2.56-2.93)

3.65 (2.50-5.31)

R

4.91 (3.37-7.16)

3.04 (2.51-3.68)

3.57 (2.30-5.55)

2000 or later

n

67

20

6

F

2.60 (2.52-2.69)

2.86 (2.72-3.01)

4.04 (2.65-6.16)

R

3.13 (2.73-3.60)

2.94 (2.50-3.47)

4.57 (2.05-10.20)

Between levels

P_B

< 0.001

< 0.001

< 0.01

Study type

Case-control

n

14

9

0

F

3.72 (3.09-4.48)

3.39 (2.90-3.96)

R

4.69 (2.83-7.77)

3.66 (2.77-4.83)

Prospective

n

38

12

8

F

6.46 (6.01-6.95)

2.96 (2.67-3.29)

3.61 (2.81-4.64)

R

4.34 (3.38-5.56)

3.12 (2.56-3.78)

3.12 (1.74-5.60)

Cross-sectional

n

68

92

14

F

2.53 (2.45-2.62)

2.78 (2.70-2.87)

2.39 (2.10-2.73)

R

3.00 (2.63-3.41)

3.42 (3.10-3.77)

6.60 (2.74-15.92)

Between levels

P_B

< 0.001

NS

NS

Outcome subtype

Mortality

n

31

4

5

F

6.57 (6.09-7.10)

4.16 (2.67-6.48)

3.79 (2.87-5.00)

R

4.57 (3.39-6.15)

4.96 (2.43-10.12)

3.42 (1.60-7.35)

Lung function (COPD) or symptoms (CB)

n

56

81

0

F

2.41 (2.32-2.50)

3.06 (2.95-3.17)

R

2.79 (2.42-3.20)

3.63 (3.29-3.99)

Other

n

33

28

17

F

3.45 (3.21-3.70)

2.24 (2.12-2.37)

2.42 (2.13-2.74)

R

3.77 (3.01-4.72)

2.69 (2.26-3.21)

5.56 (2.65-11.68)

Between levels

P_B

< 0.001

< 0.001

NS

How asthma taken into account

Ignored

n

72

103

19

F

3.78 (3.64-3.92)

2.80 (2.72-2.89)

2.59 (2.30-2.91)

R

3.60 (3.08-4.20)

3.38 (3.08-3.70)

5.02 (2.80-9.00)

Excluded

n

17

6

3

F

1.79 (1.69-1.90)

2.85 (2.53-3.21)

4.03 (1.85-8.77)

R

3.05 (2.34-3.97)

3.30 (2.39-4.54)

3.90 (0.57-26.55)

Included in outcome definition

n

18

-

-

F

2.11 (1.88-2.37)

R

2.73 (2.10-3.55)

Other

n

13

4

0

F

4.00 (3.42-4.67)

6.93 (4.39-10.92)

R

4.03 (2.96-5.48)

5.70 (2.63-12.37)

Between levels

P_B

< 0.001

NS

NS

Number of cases

1-50

n

21

18

8

F

4.62 (3.42-6.24)

3.85 (2.81-5.28)

2.09 (1.31-3.34)

R

4.90 (3.34-7.18)

3.85 (2.81-5.28)

2.09 (1.31-3.34)

51-100

n

23

14

6

F

3.08 (2.64-3.60)

4.92 (3.84-6.30)

4.83 (3.06-7.61)

R

3.21 (2.48-4.16)

5.28 (3.88-7.03)

5.14 (2.53-10.45)

101-200

n

29

19

1

F

2.61 (2.35-2.89)

3.93 (3.41-4.52)

14.50 (4.63-45.41)

R

2.92 (2.39-3.57)

4.71 (3.37-6.57)

14.50 (4.63-45.41)

201+

n

47

62

7

F

3.02 (2.92-3.12)

2.74 (2.66-2.83)

2.48 (2.19-2.81)

R

3.66 (3.02-4.43)

3.06 (2.78-3.27)

6.62 (2.44-18.00)

Between levels

P_B

NS

< 0.05

NS

Analysis type

Prevalence

n

84

103

14

F

2.57 (2.48-2.65)

2.82 (2.74-2.91)

2.39 (2.10-2.73)

R

3.14 (2.78-3.56)

3.44 (3.14-3.77)

6.60 (2.74-15.92)

Onset

n

36

10

8

F

6.58 (6.11-7.09)

2.75 (2.42-3.13)

3.61 (2.81-4.64)

R

4.40 (3.41-5.69)

3.00 (2.31-3.89)

3.12 (1.74-5.60)

Between levels

P_B

< 0.001

NS

NS

Smoking product

Any

n

46

57

5

F

3.09 (2.92-3.26)

2.84 (2.72-2.96)

2.05 (1.78-2.36)

R

3.67 (3.05-4.40)

3.54 (3.17-3.97)

3.84 (1.20-12.22)

Cigarettes (ignoring other products)

n

66

52

16

F

2.67 (2.57-2.77)

2.79 (2.67-2.91)

4.37 (3.54-5.40)

R

3.06 (2.60-3.60)

3.27 (2.84-3.76)

5.11 (2.45-10.65)

Cigarettes only

n

8

4

1

F

8.51 (7.55-9.59)

3.27 (2.55-4.20)

7.72 (2.39-24.94)

R

7.47 (4.63-12.05)

3.36 (2.24-5.05)

7.72 (2.39-24.94)

Between levels

P_B

< 0.001

NS

NS

Unexposed base^c

Never any product

n

58

69

7

F

4.07 (3.89-4.26)

2.89 (2.77-3.01)

2.41 (2.11-2.77)

R

4.27 (3.51-5.19)

3.56 (3.20-3.96)

8.93 (1.83-43.50)

Never cigarettes

n

62

44

15

F

2.34 (2.25-2.44)

2.74 (2.63-2.87)

3.18 (2.56-3.96)

R

2.87 (2.48-3.31)

3.21 (2.77-3.72)

3.30 (2.39-4.56)

Between levels

P_B

< 0.001

NS

NS

RR adjusted for age

Yes

n

63

65

13

F

3.47 (3.30-3.65)

2.57 (2.48-2.67)

2.52 (2.23-2.85)

R

3.66 (3.07-4.36)

3.05 (2.74-3.39)

5.77 (2.77-12.02)

No

n

57

48

9

F

2.76 (2.66-2.87)

3.33 (3.17-3.51)

3.57 (2.49-5.14)

R

3.34 (2.76-4.04)

4.10 (3.57-4.71)

3.35 (1.90-5.91)

Between levels

P_B

< 0.1

< 0.001

NS

RR adjusted for factors other than age or sex

Yes

n

27

29

6

F

2.77 (2.61-2.94)

2.77 (2.65-2.88)

1.87 (1.62-2.15)

R

3.17 (2.65-3.80)

2.97 (2.57-3.44)

2.62 (1.65-4.17)

No

n

93

84

16

F

3.09 (2.98-3.20)

2.87 (2.75-3.00)

5.27 (4.30-6.46)

R

3.66 (3.11-4.31)

3.68 (3.29-4.12)

5.57 (2.67-11.62)

Between levels

P_B

NS

NS

< 0.05