CANCERS
|
India
|
2001–2004
|
Case–control
|
Smokeless tobacco with or without additives
|
No/No
|
Oral cancer
|
0.49 (0.32–0.75)
|
Exclusive SLT users
|
Selection****
|
Anantharaman et al. 2007 [46]
|
Comparability**
|
Exposure/Outcome*
|
India
|
1996–1999
|
Case–control
|
Ever SLT users
|
Yes/Yes
|
Oral cancer
|
7.31 (3.79–14.1)
|
Never drinkers adjusted for smoking
|
Selection****
|
Balaram et al. 2002 [47]
|
9.19 (4.38–19.28)
|
Never smokers adjusted for alcohol
|
Comparability**
|
Exposure/Outcome *
|
India
|
1982–1992
|
Case–control
|
Tobacco quid chewing
|
Yes/No
|
Oral cancer
|
5.8 (3.6–9.34)
|
Adjusted for smoking
|
Selection***
|
Dikshit & Kanhere 2000 [48]
|
Pharyngeal cancer
|
1.2 (0.8–1.8)
|
Comparability*
|
Lung cancer
|
0.7 (0.4–1.22)
|
Exposure/Outcome*
|
India
|
Unclear
|
Case–control
|
Chewing tobacco
|
No/No
|
Oral cancer
|
10.75 (6.58–17.56)
|
Exclusive SLT users
|
Selection**
|
Goud et al. 1990 [49]
|
Comparability*
|
Exposure/Outcome0
|
India
|
1990–1997
|
Cohort
|
Current SLT users
|
No/No
|
Oral cancer
|
5.5 (3.3–9.17)
|
Exclusive SLT users
|
Selection****
|
Jayalekshmi et al. 2009 [50]
|
Former SLT users
|
9.2 (4.6–18.40)
|
Comparability*
|
Exposure/Outcome**
|
India
|
1990–1997
|
Cohort
|
Current SLT user
|
Yes/Yes
|
Oral cancer
|
2.4 (1.7–3.39)
|
Adjusted for smoking and alcohol
|
Selection****
|
Jayalekshmi et al. 2010 [51]
|
Former SLT users
|
2.1 (1.3–3.39)
|
Comparability*
|
Exposure/Outcome***
|
India
|
May 2005
|
Case–control
|
Ever SLT users
|
No/No
|
Oral cancer
|
4.23 (3.11–5.75)
|
Exclusive SLT users
|
Selection***
|
Jayant et al. 1977 [52]
|
Pharyngeal cancer
|
2.42 (1.74–3.37)
|
Comparability**
|
Laryngeal cancer
|
2.8 (2.07–3.79)
|
Exposure/Outcome0
|
Oesophageal cancer
|
1.55 (1.15–2.07)
|
India
|
1968
|
Case–control
|
Tobacco
|
Yes/No
|
Oral cancer
|
4.63 (3.50–6.14)
|
Exclusive chewers and non-chewers data available
|
Selection***
|
Jussawalla & Deshpande 1971 [53]
|
Pharyngeal cancer
|
3.09 (2.31–4.13)
|
Comparability**
|
Laryngeal cancer
|
2.29 (1.72–3.05)
|
Exposure/Outcome0
|
Oesophageal cancer
|
3.82 (2.84–5.13)
|
India
|
2005–2006
|
Case–control
|
Tobacco flakes
|
Yes/Yes
|
Oral cancer
|
7.6 (4.9–11.79)
|
Adjusted for smoking and alcohol
|
Selection****
|
Madani et al. 2010 [54]
|
Gutkha
|
12.7 (7–23.04)
|
Comparability**
|
Mishiri
|
3.0 (1.9–4.74)
|
Exposure/Outcome*
|
India
|
Unclear
|
Case–control
|
Chewing tobacco
|
Yes/Yes
|
Oral cancer
|
5.0 (3.6–6.94)
|
Adjusted for smoking and alcohol
|
Selection****
|
Muwonge et al. 2008 [55]
|
Comparability*
|
Exposure/Outcome*
|
India
|
1982–1984
|
Case–control
|
Chewing tobacco
|
Yes/No
|
Oral cancer
|
10.2 (2.6–40.02)
|
Adjusted for smoking
|
Selection***
|
Nandakumar et al. 1990 [56]
|
Comparability**
|
Exposure/Outcome*
|
India
|
1980–1984
|
Case–control
|
SLT users
|
No/No
|
Oral cancer
|
1.99 (1.41–2.81)
|
Exclusive SLT users
|
Selection**
|
Rao et al. 1994 [57]
|
Comparability0
|
Exposure/Outcome*
|
India
|
1952–1954
|
Case–control
|
Chewing tobacco
|
No/No
|
Oral cancer
|
4.85 (2.32–10.14)
|
Exclusive SLT users
|
Selection***
|
Sanghvi et al. 1955 [58]
|
Pharyngeal cancer
|
2.02 (0.94–4.33)
|
Comparability**
|
Laryngeal cancer
|
0.76 (0.37–1.56)
|
Exposure/Outcome0
|
India
|
1983–1984
|
Case–control
|
Snuff (males only)
|
Yes/Yes
|
Oral cancer
|
2.93 (0.98–8.76)
|
Adjusted for smoking and alcohol; adjusted effect size is only among males
|
Selection***
|
Sankaranarayan et al. 1990 [59]
|
Comparability0
|
Exposure/Outcome*
|
India
|
Not given
|
Case–control
|
Tobacco chewing
|
Yes/Yes
|
Oropharyngeal cancer
|
7.98 (4.11–13.58)b
|
Adjusted for smoking and alcohol
|
Selection***
|
Wasnik et al. 1998 [60]
|
Comparability**
|
Exposure/Outcome0
|
India
|
1991–2003
|
Case–control
|
Chewing tobacco
|
No/No
|
Oral cancer
|
5.88 (3.66–7.93)
|
Exclusive SLT users
|
Selection****
|
Subapriya e al. 2007 [61]
|
Comparability**
|
Exposure/Outcome**
|
India
|
1950–1962
|
Case–control
|
Tobacco with or without paan or lime
|
Yes/No
|
Oral and oropharyngeal cancer
|
41.90 (34.20–51.33)
|
Exclusive chewer data available
|
Selection**
|
Wahi et al. 1965 [62]
|
Note: data of habit was not available for the whole cohort
|
Comparability**
|
Exposure/Outcome0
|
Pakistan
|
1996–1998
|
Case–control
|
Naswar
|
Yes/Yes
|
Oral cancer
|
9.53 (1.73–52.50)
|
Adjusted for smoking and alcohol
|
Selection***
|
Merchant et al. 2000 [63]
|
Paan with tobacco
|
8.42 (2.31–30.69)
|
Comparability**
|
Exposure/Outcome*
|
Sweden
|
1973–2002
|
Cohort
|
Snus
|
Yes/Yes
|
Oral and pharyngeal combined
|
3.10 (1.50–6.41)
|
Adjusted for smoking and alcohol
|
Selection**
|
Roosar et al. 2008 [64]
|
Comparability**
|
Outcome***
|
India
|
1993–1999
|
Case–control
|
Chewing tobacco
|
Yes/Yes
|
Oral cancer
|
5.05 (4.26–5.99)
|
Adjusted for smoking and alcohol
|
Selection***
|
Znaor et al. 2003 [65]
|
Pharynx
|
1.83 (1.43–2.34)
|
Comparability**
|
Oesophagus
|
2.06 (1.62–2.62)
|
Exposure/Outcome*
|
Norway
|
1966–2001
|
Cohort
|
Chewing tobacco plus oral snuff
|
No/No
|
Oral cancer
|
1.1 (0.5–2.42)
|
Adjusted for smoking, might be confounded by alcohol use
|
Selection***
|
Bofetta et al. 2005 [66]
|
Oesophageal cancer
|
1.4 (0.61–3.21)
|
Comparability*
|
Pancreatic cancer
|
1.67 (1.12–2.49)
|
Exposure/Outcome***
|
Lung cancer
|
0.80 (0.61–1.05)
|
Sweden
|
1988–1991
|
Case–control
|
Oral snuff
|
Yes/Yes
|
Oral cancer
|
1.4 (0.8–2.45)
|
Adjusted for smoking and alcohol
|
Selection**
|
Lewin et al. 1998 [67]
|
Larynx
|
0.9 (0.5–1.62)
|
Comparability**
|
Oesophagus
|
1.2 (0.7–2.06)
|
Exposure/Outcome*
|
Pharynx
|
0.7 (0.4–1.22)
|
Sweden
|
1969–1992
|
Cohort
|
Snus
|
No/No
|
Oral cancer
|
0.8 (0.4–1.60)
|
Exclusive SLT users
|
Selection***
|
Luo et al. 2007 [68]
|
Lung cancer
|
0.8 (0.5–1.28)
|
Comparability*
|
Pancreatic cancer
|
2 (1.20–3.33)
|
Exposure/Outcome***
|
Sweden
|
2000–2004
|
Case–control
|
Oral snuff
|
Yes/Yes
|
Oral
|
0.70 (0.3–1.63)
|
Adjusted for smoking and alcohol
|
Selection***
|
Rosenquist et al 2005 [69]
|
Comparability**
|
Exposure/Outcome**
|
Sweden
|
1980–1989
|
Case–control
|
Oral snuff
|
Yes/Yes
|
Oral cancer
|
0.8 (0.5–1.28)
|
Adjusted for smoking and alcohol
|
Selection**
|
Schildt et al. 1998 [70]
|
Comparability**
|
Exposure/Outcome***
|
USA
|
1972–1983
|
Case–control
|
Oral snuff
|
Yes/Yes
|
Oral cancer
|
0.8 (0.4–1.60)
|
Not clear if adjusted for smoking and alcohol
|
Selection**
|
Mashberg et al. 1993 [71]
|
Chewing tobacco
|
1 (0.7–1.43)
|
Comparability0
|
Exposure/Outcome*
|
USA
|
Not given
|
Case–control
|
SLT use
|
Yes/Yes
|
Oral cancer
|
0.90 (0.38–2.13)
|
Adjusted for smoking and alcohol
|
Selection***
|
Zhou et al. 2013 [15]
|
Pharyngeal cancer
|
1.59 (0.84–3.01)
|
Comparability**
|
Laryngeal cancer
|
0.67 (0.19–2.36)
|
Exposure/Outcome*
|
India
|
2001–2004
|
Case–control
|
Chewing tobacco
|
No/No
|
Pharyngeal cancer
|
3.18 (1.92–5.27)
|
Exclusive SLT users
|
Selection***
|
Sapkota et al. 2007 [72]
|
Laryngeal cancer
|
0.95 (0.52–1.74)
|
Comparability**
|
Exposure/Outcome*
|
Pakistan
|
1998–2002
|
Case–control
|
Snuff dipping
|
No/No
|
Oesophageal cancer
|
4.1 (1.3–12.93)
|
Adjusted for areca nut
|
Selection***
|
Akhtar et al. 2012 [73]
|
Quid with tobacco
|
14.2 (6.4–31.50)
|
Comparability**
|
Exposure/Outcome**
|
India
|
2008–2012
|
Case–control
|
Nass chewing
|
No/No
|
Oesophageal cancer
|
2.88 (2.06–4.03)
|
Exclusive SLT users
|
Selection***
|
Dar et al. 2012 [74]
|
Gutkha chewing
|
2.87 (0.87–9.47)
|
Comparability**
|
Exposure/Outcome**
|
India
|
2007–2011
|
Case–control
|
Oral snuff
|
Yes/Yes
|
Oesophageal cancer
|
3.86 (2.46–6.06)
|
Adjusted for smoking and alcohol
|
Selection**
|
Sehgal et al. 2012 [75]
|
Comparability**
|
Exposure/Outcome*
|
India
|
2011–2012
|
Case–control
|
Chewing tobacco
|
Yes/Yes
|
Oesophageal cancer
|
2.63 (1.53–4.52)
|
Adjusted for smoking and alcohol
|
Selection***
|
Talukdar et al. 2013 [76]
|
Comparability**
|
Exposure/Outcome*
|
Sweden
|
1995–1997
|
Case–control
|
Oral snuff
|
Yes/Yes
|
Oesophageal cancer (adenocarcinoma)
|
1.2 (0.7–2.06)
|
Adjusted for smoking and alcohol
|
Selection***
|
Lagergren et al. 2000 [77]
|
(Squamous cell carcinoma)
|
1.4 (0.9–2.18)
|
Comparability**
|
Exposure/Outcome*
|
Sweden
|
1969–1993
|
Cohort
|
Oral snuff
|
Yes/No
|
Oesophageal cancer (Adenocarcinoma)
|
1.3 (0.8–2.11)
|
Adjusted for smoking
|
Selection**
|
Zendehdel et al. 2008 [78]
|
(Squamous cell carcinoma)
|
1.2 (0.8–1.80)
|
Comparability*
|
Exposure/Outcome**
|
Sweden
|
1974–1985
|
Cohort
|
SLT users
|
No/NA
|
Lung cancer
|
0.90 (0.20– 4.05)
|
Adjusted for age, region of origin
|
Selection***
|
Bolinder et al. 1994 [79]
|
Comparability*
|
Outcome**
|
Morocco
|
1996–1998
|
Case–control
|
SLT users
|
Yes/No
|
Lung cancer
|
1.05 (0.28–3.94)
|
Adjusted for smoking
|
Selection**
|
Sasco et al. 2002 [80]
|
Comparability**
|
Exposure/Outcome**
|
USA
|
1977–1984
|
Case–control
|
SLT users
|
Yes/No
|
Oesophageal cancer
|
1.2 (0.1–14.40)
|
Adjusted for smoking
|
Selection***
|
Brown et al. 1988 [81]
|
Comparability**
|
Exposure/Outcome**
|
USA
|
1986–1989
|
Case–control
|
SLT users
|
Yes/No
|
Pancreatic cancer
|
1.4 (0.5–3.92)
|
Adjusted for smoking
|
Selection***
|
Alguacil & Silverman 2004 [82]
|
Comparability*
|
Exposure/Outcome**
|
USA
|
2000–2006
|
Case–control
|
Chewing tobacco
|
Yes/Yes
|
Pancreatic cancer
|
0.6 (0.3–1.20)
|
Adjusted for smoking and alcohol
|
Selection****
|
Hassan et al. 2007 [83]
|
Oral snuff
|
0.5 (0.1–2.5)
|
Comparability**
|
Exposure/Outcome*
|
CARDIOVASCULAR DISEASES (ischaemic heart disease and stroke)
|
52 countries
|
1999–2003
|
Case–control
|
Chewing tobacco
|
No/Yes
|
Myocardial infarction
|
1.57 (1.24–1.99)
|
Adjusted for diabetes, abdominal obesity, hypertension, exercise, diet
|
Selection****
|
Teo et al. 2006 [29]
|
Comparability**
|
Exposure/Outcome*
|
Pakistan
|
2005–2011
|
Case–control
|
Dippers only (Naswar)
|
No/NA
|
Myocardial infarction
|
1.46 (1.20–1.77)
|
Adjusted for age, sex, region, ethnicity
|
Selection****
|
Alexander 2013 [84]
|
Chewers only (Paan/ Supari/ Gutkha)
|
1.71 (1.46–2.00)
|
Comparability**
|
Exposure/Outcome**
|
Bangladesh
|
2006–2007
|
Case–control
|
Ever SLT users
|
No/NA
|
Myocardial infarction, Angina pectoris
|
2.8 (1.1–7.13)
|
Adjusted for age, sex, hypertension
|
Selection***
|
Rahman & Zaman 2008 [85]
|
Comparability**
|
Exposure/Outcome*
|
Bangladesh
|
2010
|
Case–control
|
Ever SLT users
|
No/NA
|
Myocardial infarction, Angina pectoris
|
0.77 (0.52–1.14)
|
Adjusted for age, hypertension, diabetes, acute psycho-social stress
|
Selection****
|
Rahman et al. 2012 [86]
|
Comparability**
|
Exposure/Outcome*
|
Sweden
|
1998–2005
|
Case–control
|
Current SLT users
|
No/NA
|
Myocardial infarction
|
0.73 (0.35–1.52)
|
Exclusive SLT users
|
Selection***
|
Hergens et al. 2005 [87]
|
Former SLT users
|
1.2 (0.46–3.13)
|
Comparability**
|
Exposure/Outcome**
|
Sweden
|
1978–2004
|
Cohort
|
Ever SLT users
|
No/NA
|
Myocardial infarction
|
0.99 (0.90–1.10)
|
Adjusted for age, BMI, region of residence
|
Selection**
|
Hergens et al. 2007 [88]
|
Comparability**
|
Exposure/Outcome***
|
Sweden
|
1989–1991
|
Case–control
|
Regular SLT users
|
Yes/NA
|
Myocardial infarction
|
1.01 (0.66–1.55)c
|
Adjusted for age, education, smoking
|
Selection***
|
Huhtasaari et al. 1992 [89]
|
Comparability**
|
Exposure/Outcome*
|
Sweden
|
1991–1993
|
Case–control
|
Former SLT users
|
No/NA
|
Myocardial infarction
|
1.23 (0.54–2.82)
|
Exclusive SLT users
|
Selection****
|
Huhtasaari et al. 1999 [90]
|
Comparability**
|
Exposure/Outcome**
|
Sweden
|
1988–2000
|
Cohort
|
Daily SLT users
|
No/NA
|
Ischaemic heart disease
|
1.41 (0.61–3.28)
|
Adjusted for BMI, physical activity, diabetes, hypertension
|
Selection****
|
Johansson et al. 2005 [91]
|
Comparability**
|
Exposure/Outcome**
|
Sweden
|
1985–1999
|
Case–control
|
Current SLT users
|
No/NA
|
Myocardial infarction
|
0.82 (0.46–1.46)
|
Adjusted for BMI, physical activity, education, cholesterol
|
Selection****
|
Wennberg et al. 2007 [92]
|
Former SLT users
|
0.66 (0.32–1.36)
|
Comparability**
|
Exposure/Outcome**
|
Sweden
|
1985–2000
|
Case–control
|
Regular SLT users
|
No/NA
|
Stroke
|
0.87 (0.41–1.83)
|
Adjusted for diabetes, hypertension, education, marital status, cholesterol
|
Selection****
|
Asplund et al. 2003 [93]
|
Comparability**
|
Exposure/Outcome**
|
Sweden
|
1978–2003
|
Cohort
|
Ever SLT users
|
No/NA
|
Stroke
|
1.02 (0.92–1.13)
|
Adjusted for age, BMI, region of residence
|
Selection**
|
Hergens et al. 2008 [94]
|
Comparability**
|
Exposure/Outcome***
|
Sweden
|
1998–2005
|
Cohort
|
Current SLT users
|
No/NA
|
Ischaemic heart disease
|
0.85 (0.51–1.42)
|
Adjusted for age, hypertension, diabetes, cholesterol
|
Selection***
|
Hansson et al. 2009 [95]
|
Former SLT users
|
Stroke
|
1.07 (0.56–2.04)
|
Comparability**
|
1.18 (0.67–2.08)
|
Exposure/Outcome**
|
1.35 (0.65–2.82)
|
Sweden
|
1991–2004
|
Cohort
|
SLT users
|
No/NA
|
Myocardial infarction
|
0.75 (0.3–1.87)
|
Adjusted for age, diabetes, occupation, hypertension, physical activity, BMI, marital status
|
Selection***
|
Janzon et al. 2009 [96]
|
Stroke
|
0.59 (0.2–1.5)
|
Comparability**
|
Exposure/Outcome**
|