6. Detailed summary results of included nonexperimental case‐control studies.
| References | Detailed summary results | The Newcastle‐Ottawa Scale (NOS) |
| Bandera 2010 | Reference category: lowest exposure Endometrial cancer Intermediate exposure: OR 1.04 (95% CI 0.72‐1.50) Highest exposure: OR 0.76 (95% CI 0.48‐1.21) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, difference in response rate between cases and controls or no designation Total score: 8/9 stars, moderate quality. |
| Berroukche 2012 | Reference category: lowest exposure Prostate cancer Intermediate exposure 1: OR 1.4 (95% CI 0.8‐2.2) Intermediate exposure 2: OR 0.9 (95% CI 0.5‐1.4) Highest exposure: OR 0.6 (95% CI 0.3‐1.1) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 8/9 stars, moderate quality. |
| Bonner 2005 | Reference category: lowest exposure Lung cancer Intermediate exposure: OR 0.84 (95% CI 0.38‐1.85) Highest exposure: OR 0.59 (95% CI 0.26‐1.37) |
Low risk: Selection: 3/4 stars, no description of source of controls Comparability: 2/2 stars, low risk Exposure: 2/3 stars, low risk Total score: 7/9 stars, moderate quality. |
| Chen 2011 | Oesophageal cancer Reference category: lowest exposure Intermediate exposure 1: OR 1.27 (95% CI 0.72‐1.89) Intermediate exposure 2: OR 0.97 (95% CI 0.59‐2.56) Highest exposure: OR 0.92 (95% CI 0.49‐2.32) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 8/9 stars, moderate quality. |
| Chen 2017a | Oral cancer Reference category: lowest exposure Chen 2015 Highest exposure: OR 0.48 (95% CI 0.28‐0.82) Chen 2016 Highest exposure: OR 0.501 (95% CI 0.284‐0.883) Chen 2017a non‐smokers Highest exposure: OR 0.515 (95% CI 0.323‐0.821) Former/current smokers Highest exposure: OR 0.849 (95% CI 0.556‐1.298) Non‐alcohol drinkers Highest exposure: OR 0.551 (95% CI 0.372‐0.817) Former/current alcohol drinkers Highest exposure: OR 0.934 (95% CI 0.934‐1.563) |
Low risk: Chen 2015 Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 9/9 stars, high quality. Chen 2016 Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 8/9 stars, moderate quality. Chen 2017a Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 8/9 stars, moderate quality. |
| Fu 2013 | Oral cancer Reference category: lowest exposure Men Intermediate exposure: OR 0.82 (95% CI 0.69‐1.07) Highest exposure: OR 0.72 (95% CI 0.54‐0.93) Women Intermediate exposure: OR 1.00 (95% CI 0.80‐1.25) Highest exposure: OR 0.93 (95% CI 0.74‐1.26) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 8/9 stars, moderate quality. |
| Gao 1994 | Oesophageal cancer Reference category: lowest exposure Exposure assessment A: intake of green tea Men Highest exposure: OR 0.80 (95% CI 0.58‐1.09) Women Highest exposure: OR 0.50 (95% CI 0.30‐0.83) Exposure assessment B: green tea consumption Men Intermediate exposure: OR 0.79 (95% CI 0.53‐1.17) Highest exposure: OR 0.79 (95% CI 0.56‐1.13) Women Intermediate exposure: OR 0.77 (95% CI 0.39‐1.53) Highest exposure: OR 0.34 (95% CI 0.17‐0.69) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate difference between cases and controls or NR Total score: 7/9 stars, moderate quality. |
| Gao 2005 | Reference category: lowest exposure Endometrial cancer Highest exposure: OR 0.81 (95% CI 0.65‐1.00) |
Low risk: Selection: 4/4 stars, low risk Comparability: 1/2 stars, the study did not control for smoking. Exposure: 2/3 stars, nonresponse rate different between cases and controls or NR Total score: 7/9 stars, moderate quality. |
| Gavrilas 2018 | Colorectal cancer Reference category: lowest exposure Intermedaite exposure 1: OR 0.34 (95% CI 0.15‐0.76) Intermediate exposure 2: OR 0.03 (95% CI 0.01‐0.10) Highest exposure: OR 0.14 (95% CI 0.05‐0.34) |
Low risk: Selection: 3/4 stars, no description of controls Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate NR Total score: 7/9 stars, moderate quality. |
| Goodman 2003 | Ovarian cancer Reference category: lowest exposure Highest exposure: OR 0.9 (95% CI 0.6‐1.5) Highest exposure A: OR 1.0 (95% CI 0.6‐1.9) Highest exposure B: OR 0.9 (95% CI 0.5‐1.6) |
Low risk: Selection: 4/4 stars, low risk Comparability: 1/2 stars, the study did not control for smoking Exposure: 3/3 stars, low risk Total score: 8/9 stars, moderate quality. |
| Goto 1990 | Pancreatic cancer Reference category: lowest exposure Highest exposure: OR 0.34 (95% CI 0.17‐0.67) |
Low risk: Selection: 3/4 stars, no description of source of controls Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 7/9 stars, moderate quality. |
| Green 2014 | Reference category: lowest exposure Colorectal cancer Intermediate exposure 1: OR 0.99 (95% CI 0.64‐1.52) Intermediate exposure 2: OR 1.15 (95% CI 0.62‐2.13) Highest exposure: OR 0.99 (95% CI 0.62‐1.58) Proximal colon cancer Intermediate exposure 1: OR 1.36 (95% CI 0.76‐2.41) Intermediate exposure 2: OR 0.61 (95% CI 0.20‐1.83) Highest exposure: OR 0.95 (95% CI 0.50‐1.78) Distal colon cancer Intermediate exposure 1: OR 0.75 (95% CI 0.38‐1.46) Intermediate exposure 2: OR 1.31 (95% CI 0.55‐3.10) Highest exposure: OR 0.97 (95% CI 0.47‐2.03) Rectal cancer Intermediate exposure 1: OR 0.91 (95% CI 0.48‐1.71) Intermediate exposure 2: OR 1.49 (95% CI 0.67‐3.32) Highest exposure: OR 1.05 (95% CI 0.53‐2.10) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 8/9 stars, moderate quality. |
| Hakim 2000 | Skin cancer Reference category: lowest exposure Highest exposure: OR 0.82 (95% CI 0.35‐1.90) |
Low risk: Selection: 4/4 stars, low risk Comparability: 1/2 stars, the study did not control for smoking. Exposure: 3/3 stars, low risk Total score: 8/9 stars, moderate quality. |
| Han 2008 | Reference category: lowest exposure Lung cancer Exposure assessment 1: Highest exposure: OR 0.520 (95% CI 0.392‐0.691) Exposure assessment 2: Intermediate exposure 1: OR 0.222 (95% CI 0.127‐0.390) Intermediate exposure 2: OR 0.687 (95% CI 0.448‐1.052) Highest exposure: OR 0.734 (95% CI 0.476‐1.132) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 8/9 stars, moderate quality. |
| Hemelt 2010 | Bladder cancer Reference category: lowest exposure Exposure assessment 1: Highest exposure: OR 0.95 (95% CI 0.68‐1.32) Exposure assessment 2: Intermediate exposure: OR 0.83 (95% CI 0.54‐1.27) Highest exposure: OR 1.02 (95% CI 0.71‐1.48) further divided by cups/d: < 4 cups/d OR 1.23 (95% CI 0.76‐1.97); > 4 cups/d OR 0.83 (95% CI 0.53‐1.28) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 7/9 stars, moderate quality. |
| Hoshiyama 1992 | Reference category: lowest exposure Single stomach cancer Intermediate exposure: OR 1.2 (95% CI 0.8‐1.7) Highest exposure: OR 0.9 (95% CI 0.6‐1.3) Multiple stomach cancer Intermediate exposure: OR 1.5 (95% CI 0.6‐3.5) Highest exposure: OR 1.6 (95% CI 0.7‐3.9) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 3/3 stars, non‐response rate different between cases and controls or NR Total score: 8/9 stars, moderate quality. |
| Hsu 2012 | Reference category: lowest exposure Nasopharyngeal carcinoma Intermediate exposure: OR 0.58 (95% CI 0.35‐0.98) Highest exposure: OR 0.61 (95% CI 0.40‐0.91) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 8/9 stars, moderate quality. |
| Huang 1999 |
Huang 1999 Reference category: lowest exposure Stomach cancer Intermediate exposure 1: OR 0.88 (95% CI 0.73‐1.05) Intermediate exposure 2: OR 1.08 (95% CI 0.90‐1.24) Highest exposure: OR 0.90 (95% CI 0.73‐1.11) Inoue 1994 Reference category: lowest exposure Stomach cancer (total) Highest exposure: OR 1.09 (95% CI 0.83‐1.43) Subsite Cardia Highest exposure: OR 1.12 (95% CI 0.70‐1.79) Middle Highest exposure: OR 1.06 (95% CI 0.73‐1.54) Antrum Highest exposure: OR 1.10 (95% CI 0.78‐1.57) Kato 1990a Reference category: lowest exposure Stomach cancer Men Intermediate exposure: RR 1.14 (95% CI 0.82‐1.60) Highest exposure: RR 1.01 (95% CI 0.70‐1.47) Women Intermediate exposure: RR 0.71 (95% CI 0.45‐1.14) Highest exposure: RR 0.81 (95% CI 0.51‐1.27) |
High risk: Huang 1999 Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐respondent described Total score: 7/9 stars, moderate quality. Kato 1990a Selection: 2/4 stars, potential bias in selection of cases and hospital controls Comparability: 1/2 stars, the study did not control for smoking. Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 5/9 stars, low quality. Inoue 1994 Selection: 3/4 stars, hospital controls Comparability: 1/2 stars, the study did not control for smoking. Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 6/9 stars, low quality. |
| Inoue 1998 | Reference category: lowest exposure Oesophageal cancer Intermediate exposure 1: OR 1.02 (95% CI 0.50‐2.10) Intermediate exposure 2: OR 1.07 (95% CI 0.58‐2.00) Intermediate exposure 3: OR 0.96 (95% CI 0.50‐1.83) Highest exposure: OR 1.14 (95% CI 0.55‐2.34) Stomach cancer (also reported in Inoue 1994 in: Huang 1999 and Inoue 2009a) Intermediate exposure 1: OR 1.00 (95% CI 0.77‐1.44) Intermediate exposure 2: OR 0.96 (95% CI 0.70‐1.32) Intermediate exposure 3: OR 1.01 (95% CI 0.74‐1.39) Highest exposure: OR 0.69 (95% CI 0.48‐1.00) Colon cancer Intermediate exposure 1: OR 0.62 (95% CI 0.36‐1.05) Intermediate exposure 2: OR 0.64 (95% CI 0.42‐1.00) Intermediate exposure 3: OR 0.76 (95% CI 0.49‐1.17) Highest exposure: OR 0.77 (95% CI 0.47‐1.26) Rectal cancer Intermediate exposure 1: OR 1.41 (95% CI 0.70‐2.83) Intermediate exposure 2: OR 1.04 (95% CI 0.55‐1.98) Intermediate exposure 3: OR 1.42 (95% CI 0.75‐2.69) Highest exposure: OR 1.25 (95% CI 0.62‐2.51) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 7/9 stars, moderate quality. |
| Inoue 2008 | Reference category: lowest exposure Breast cancer Intermediate exposure: OR 0.65 (95% CI 0.45‐0.94) Highest exposure: OR 1.00 (95% CI 0.82‐1.22) |
Low risk: Selection: 4/4 stars, low risk Comparability: 1/2 stars, the study did not control for smoking Exposure: 2/3 stars, non‐response rate different between cases and controls Total score: 7/9 stars, moderate quality. |
| Islami 2009 | Reference category: lowest exposure Oesophageal cancer Highest exposure: OR 0.89 (95% CI 0.38‐2.09) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐respondents described Total score: 8/9 stars, moderate quality. |
| Iwasaki 2014 | Reference category: lowest exposure Breast cancer Intermediate exposure: OR 0.86 (95% CI 0.53‐1.41) Highest exposure: OR 1.27 (95% CI 0.75‐2.14) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐respondents described Total score: 7/9 stars, moderate quality. |
| Ji 1996 | Reference category: lowest exposure Stomach cancer Men Exposure assessment A: green tea drinking status Highest exposure: OR 0.96 (95% CI 0.77‐1.21) Exposure assessment B: consumption of green tea leaves Intermediate exposure 1: OR 1.06 (95% CI 0.76‐1.49) Intermediate exposure 2: OR 1.15 (95% CI 0.82‐1.61) Intermediate exposure 3: OR 0.88 (95% CI 0.55‐1.24) Highest exposure: OR 0.76 (95% CI 0.55‐1.27) Women Exposure assessment A: green tea drinking status Highest exposure: OR 0.77 (95% CI 0.52‐1.13) Exposure assessment B: consumption of green tea leaves Intermediate exposure: OR 0.74 (95% CI 0.45‐1.21) Highest exposure: OR 0.81 (95% CI 0.46‐1.43) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 8/9 stars, moderate quality. |
| Ji 1997 | Reference category: lowest exposure Men Colon cancer Exposure assessment A: green tea drinking habit Highest exposure: OR 0.99 (95% CI 0.74‐1.33) Exposure assessment B: green tea consumption Intermediate exposure 1: OR 1.13 (95% CI 0.80‐1.61) Intermediate exposure 2: OR 0.92 (95% CI 0.62‐1.37) Highest exposure: OR 0.82 (95% CI 0.52‐1.28) Exposure assessment C: lifetime green tea consumption Intermediate exposure 1: OR 0.93 (95% CI 0.63‐1.35) Intermediate exposure 2: OR 1.06 (95% CI 0.72‐1.56) Highest exposure: OR 1.01 (95% CI 0.67‐1.51) Rectal cancer Exposure assessment A: green tea drinking habit Highest exposure: OR 0.82 (95% CI 0.61‐1.10) Exposure assessment B: green tea consumption Intermediate exposure 1: OR 0.99 (95% CI 0.69‐1.41) Intermediate exposure 2: OR 0.66 (95% CI 0.43‐0.99) Highest exposure: OR 0.72 (95% CI 0.46‐1.13) Exposure assessment C: lifetime green tea consumption Intermediate exposure 1: OR 0.88 (95% CI 0.60‐1.27) Intermediate exposure 2: OR 0.75 (95% CI 0.50‐1.13) Highest exposure: OR 0.80 (95% CI 0.53‐1.23) Pancreatic cancer Exposure assessment A: green tea drinking habit Highest exposure: OR 0.88 (95% CI 0.60‐1.31) Exposure assessment B: green tea consumption Intermediate exposure 1: OR 1.23 (95% CI 0.79‐1.92) Intermediate exposure 2: OR 0.57 (95% CI 0.32‐1.03) Highest exposure: OR 0.63 (95% CI 0.34‐1.17) Exposure assessment C: lifetime green tea consumption Intermediate exposure 1: OR 1.11 (95% CI 0.69‐1.79) Intermediate exposure 2: OR 0.86 (95% CI 0.51‐1.45) Highest exposure: OR 0.59 (95% CI 0.32‐1.07) Women Colon cancer Exposure assessment A: green tea drinking habit Highest exposure: OR 0.77 (95% CI 0.56‐1.06) Exposure assessment B: green tea consumption Intermediate exposure: OR 0.83 (95% CI 0.57‐1.21) Highest exposure: OR 0.67 (95% CI 0.41‐1.10) Exposure assessment C: lifetime green tea consumption Intermediate exposure: OR 0.87 (95% CI 0.60‐1.27) Highest exposure: OR 0.62 (95% CI 0.38‐1.02) Rectal cancer Exposure assessment A: green tea drinking habit Highest exposure: OR 0.51 (95% CI 0.36‐0.73) Exposure assessment B: green tea consumption Intermediate exposure: OR 0.51 (95% CI 0.33‐0.79) Highest exposure: OR 0.57 (95% CI 0.34‐0.97) Exposure assessment C: lifetime green tea consumption Intermediate exposure: OR 0.54 (95% CI 0.35‐0.84) Highest exposure: OR 0.52 (95% CI 0.30‐0.89) Pancreatic cancer: Exposure assessment A: green tea drinking habit Highest exposure: OR 0.47 (95% CI 0.29‐0.77) Exposure assessment B: green tea consumption Intermediate exposure: OR 0.47 (95% CI 0.25‐0.89) Highest exposure: OR 0.53 (95% CI 0.25‐1.09) Exposure assessment C: lifetime green tea consumption Intermediate exposure: OR 0.59 (95% CI 0.32‐1.10) Highest exposure: OR 0.38 (95% CI 0.18‐0.82) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐respondents described Total score: 8/9 stars, moderate quality. |
| Jia 2016 | Reference category: lowest exposure Lung cancer + mesothelioma mortality Intermediate exposure 1: OR 0.88 (95% CI 0.66‐0.87) Intermediate exposure 2: OR 2.18 (95% CI 0.96‐3.50) Highest exposure: OR 0.70 (95% CI 0.57‐0.86) |
Low risk: Selection: 4/4 stars, low risk Comparability: 1/2 stars, the study did not control for smoking Exposure: 2/3 stars, interview not blinded to case/control status Total score: 7/9 stars, moderate quality. |
| Jian 2004 | Prostate cancer Reference category: lowest exposure Exposure assessment A: green tea drinking habits Highest exposure: OR 0.28 (95% CI 0.17‐0.47) Exposure assessment B: intake of green tea Intermediate exposure: OR 0.53 (95% CI 0.30‐0.94) Highest exposure: OR 0.27 (95% CI 0.15‐0.48) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 8/9 stars, moderate quality. |
| Jin 2013 | Reference category: lowest exposure Lung cancer Exposure assessment A: green tea drinking habits Highest exposure: OR 0.78 (95% CI 0.65‐0.95) Exposure assessment B: consumption of green tea Intermediate exposure 1: OR 0.76 (95% CI 0.54‐1.07) Intermediate exposure 2: OR 0.84 (95% CI 0.66‐1.08) Highest exposure: OR 0.74 (95% CI 0.56‐0.99) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 9/9 stars, high quality. |
| Kakuta 2009 | Reference category: lowest exposure Endometrial cancer Intermediate exposure 1: OR 0.77 (95% CI 0.37‐1.58) Intermediate exposure 2: OR 0.61 (95% CI 0.30‐1.23) Highest exposure: OR 0.33 (95% CI 0.15‐0.75) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 8/9 stars, moderate quality. |
| Kato 1990 | Reference category: lowest exposure Colon cancer Highest exposure: RR 0.61 (95% CI 0.41‐0.91) Rectal cancer Highest exposure: RR 1.32 (95% CI 0.78‐2.23) |
High risk: Selection: 3/4 stars, potential for selection bias in cases Comparability: 1/2 stars, the study did not control for smoking Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 6/9 stars, low quality. |
| Kono 1988 | Stomach cancer Reference category: lowest exposure Population controls Highest exposure: OR 0.3 (95% CI 0.1‐0.7) Hospital controls Highest exposure: OR 0.5 (95% CI 0.3‐1.1) |
High risk: Selection: 4/4 stars when using population controls and 3/4 when using hospital controls Comparability: 2/2 stars, low risk Exposure: 1/3 stars, different methods of exposure ascertainment in cases and controls and self‐reported exposure not within a structured interview or questionnaire. Total score: 7/9 stars, moderate quality and 6/9 stars low quality. |
| Kubik 2008 |
Kubik 2008 Reference category: lowest exposure (OR for trend only reported) Lung cancer Men nonsmokers Highest exposure: OR 1.08 (95% CI 0.56‐2.08) Men smokers Highest exposure: OR 0.93 (95% CI 0.63‐1.38) Women nonsmokers Highest exposure: OR 0.88 (95% CI 0.61‐1.27) Women smokers Highest exposure: OR 1.09 (95% CI 0.80‐1.49) Data on former smokers who quit from 10 to < 20 years were excluded from the reported analysis. Previous report on fewer female cases reported in Kubik 2004. Kubik 2004 Reference category: lowest exposure Lung cancer Intermediate exposure: OR 0.97 (95% CI 0.69‐1.38) Highest exposure: OR 1.02 (95% CI 0.74‐1.40) Also analysis available stratified by smoking habits Subsequent report in Kubik 2008 with longer recruitment of women from the same area |
Low risk: Kubik 2004 Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 7/9 stars, moderate quality. Kubik 2008 Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 7/9 stars, moderate quality. |
| Kuo 2009 | Leukaemia Green‐tea‐only consumption compared to no‐tea consumption Cases exposed = 9, controls exposed = 24, cases not exposed = 63, controls not exposed = 123 OR 0.73 (95% CI 0.32‐1.67) Consumption of green tea with other types of tea compared to no‐tea consumption Cases exposed = 17, controls exposed = 61, cases not exposued = 63, controls not exposed = 123 OR 0.54 (95% CI 0.29‐1.01) |
High risk: Selection: 4/4 stars, low risk Comparability: 0/2 stars, only crude analysis without adjustment for confounding factors Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 6/9 stars, low quality. |
| Lassed 2016 | Reference category: lowest exposure Postate cancer Intermediate exposure: OR 0.64 (95% CI 0.36‐1.15) Highest exposure: OR 0.40 (95% CI 0.08‐1.92) |
High risk: Selection: 3/4 stars, hospital controls Comparability: 0/2 stars, crude analysis with no adjustment for confounding factors Exposure: 3/3 stars, low risk Total score: 6/9 stars, low quality. |
| Le Marchand 2000 | Reference category: lowest exposure Lung cancer Intermediate exposure 1: OR 1.0 (95% CI 0.6‐1.7) Intermediate exposure 2: OR 0.7 (95% CI 0.4‐1.3) Highest exposure: OR 0.9 (95% CI 0.5‐1.6) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 9/9 stars, high quality. |
| Lee 2017 | Reference category: lowest exposure Prostate cancer Exposure assessment A Highest exposure: OR 0.60 (95% CI 0.37‐0.98) Exposure assessment B Intermediate exposure 1: OR 1.53 (95% CI 0.39‐5.93) Intermediate exposure 2: OR 0.16 (95% CI 0.01‐2.22) Highest exposure: OR 0.34 (95% CI 0.02‐6.05) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 7/9 stars, moderate quality. |
| Lei 1994 | Reference category: lowest exposure Lung cancer Highest exposure: OR 0.71 (95% CI 0.43‐1.18) |
High risk: Selection: 1/4 stars, no description of identification of cases with potential selection bias and hospital controls Comparability: 1/2 stars, the study did not control for smoking. Exposure: 1/3 star, no description of exposure ascertainment and non‐response rate between cases and controls NR Total score: 3/9 stars, low quality. |
| Leung 2016 | Reference category: lowest exposure Ovarian cancer Exposure assessment A Highest exposure: OR 0.84 (95% CI 0.54‐1.30) Exposure assessment B Intermediate exposure 1: OR 1.03 (95% CI 0.50‐2.00) Intermediate exposure 2: OR 0.78 (95% CI 0.37‐1.55) Highest exposure: OR 0.77 (95% CI 0.39‐1.46) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 9/9 stars, high quality |
| Li 2011a | Reference category: lowest exposure Results using population controls All cancer Exposure assessment A Highest exposure: OR 0.78 (95% CI 0.60‐1.01) Exposure assessment B Intermediate exposure: OR 0.71 (95% CI 0.47‐1.08) Highest exposure: OR 0.51 (95% CI 0.27‐0.74) Breast cancer Exposure assessment A Highest exposure: OR 0.61 (95% CI 0.32‐1.18) Exposure assessment B Intermediate exposure: OR 0.60 (95% CI 0.24‐1.50) Highest exposure: OR 0.07 (95% CI 0.01‐0.47) Colorectal cancer Exposure assessment A Highest exposure: OR 0.62 (95% CI 0.42‐0.92) Exposure assessment B Intermediate exposure: OR 0.55 (95% CI 0.28‐1.06) Highest exposure: OR 0.45 (95% CI 0.25‐0.82) Leukaemia Exposure assessment A Highest exposure: OR 1.55 (95% CI 0.61‐3.96) Exposure assessment B Intermediate exposure: OR not estimable Highest exposure: OR 0.57 (95% CI 0.07‐4.79) Results using hospital controls All cancer Exposure assessment A Highest exposure: OR 0.77 (95% CI 0.59‐1.00) Exposure assessment B: Intermediate exposure: OR 0.60 (95% CI 0.40‐0.92) Highest exposure: OR 0.51 (95% CI 0.31‐0.83) Breast cancer Exposure assessment A Highest exposure: OR 0.55 (95% CI 0.28‐1.06) Exposure assessment B Intermediate exposure: OR 0.54 (95% CI 0.22‐1.33) Highest exposure: OR 0.06 (95% CI 0.01‐0.61) Colorectal cancer Exposure assessment A Highest exposure: OR 0.67 (95% CI 0.45‐0.99) Exposure assessment B Intermediate exposure: OR 0.51 (95% CI 0.26‐0.99) Highest exposure: OR 0.52 (95% CI 0.29‐0.94) Leukaemia Exposure assessment A Highest exposure: OR 1.46 (95% CI 0.55‐3.84) Exposure assessment B Intermediate exposure: OR not estimable Highest exposure: OR 0.65 (95% CI 0.08‐5.63) |
Low risk: Selection: 4/4 stars when using population controls and 3/4 when using hospital controls, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 8/9 stars and 7/9 stars, moderate quality. |
| Li 2014 | Reference category: lowest exposure Prostate cancer Highest exposure: OR 0.59 (95% CI 0.40‐0.87) |
Low risk: Selection: 4/4 stars, low risk Comparability: 1/2 stars, the study did not control for smoking Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 7/9 stars, moderate quality. |
| Li 2016 | Reference category: lowest exposure Breast cancer Highest exposure: OR 1.20 (95% CI 0.80‐1.78) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 1/2 stars, the study did not control for smoking Exposure: 3/3 stars, low risk Total score: 7/9 stars, moderate quality. |
| Lin 2012 | Reference category: highest exposure Lung cancer Intermediate exposure: RR 3.01 (95% CI 1.13‐8.05) Lowest exposure: RR 6.34 (95% CI 2.69‐14.91) |
High risk: Selection: 3/4 stars, hospital controls Comparability: 1/2 stars, the study did not control for smoking. Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 6/9 stars, low quality. |
| Liu 2010 | Reference category: lowest exposure Stomach cancer: Highest exposure: OR 0.42 (95%CI 0.32‐0.55) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 9/9 stars, high quality. |
| Liu 2017 | Reference category: highest exposure Leukaemia Lowest exposure: OR 0.71 (95% CI 0.46‐1.07) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 8/9 stars, moderate quality. |
| Mao 2011 | Reference category: lowest exposure Stomach cancer Exposure assessment A: green‐tea drinking status Intermediate exposure: OR 0.58 (95% CI 0.46‐5.03) Highest exposure: OR 1.02 (95% CI 0.70‐1.64) Exposure assessment B: green tea consumption Intermediate exposure 1: OR 0.88 (95% CI 0.57‐1.36) Intermediate exposure 2: OR 1.15 (95% CI 0.76‐2.35) Highest exposure: OR 1.13 (95% CI 0.52‐2.67) |
High risk: Selection: 2/4 stars, hospital controls with no description Comparability: 2/2 stars, low risk Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 6/9 stars, low quality. |
| Mizoo 2013 | Reference category: lowest exposure Breast cancer Intermediate exposure 1: OR 0.97 (95% CI 0.71‐1.33) Intermediate exposure 2: OR 0.63 (95% CI 0.43‐0.93) Highest exposure: OR 0.72 (95% CI 0.46‐1.12) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 1/2 stars, the study did not control for smoking Exposure: 3/3 stars, low risk Total score: 7/9 stars, moderate quality. |
| Mizuno 1992 | Reference category: lowest exposure Pancreatic cancer Highest exposure: OR 1.94 (95% CI 1.06‐3.55) |
High risk: Selection: 3/4 stars, hospital controls Comparability: 1/2 stars, the study did not control for smoking Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 6/9 stars, low quality. |
| Mu 2003 | Reference category: lowest exposure Stomach cancer (Mu 2005) Intermediate exposure 1: OR 1.09 (95% CI 0.53‐2.23) Intermediate exposure 2: OR 0.44 (95% CI 0.19‐1.01) Highest exposure: OR 0.40 (95% CI 0.14‐1.09) Exposure assessment B: green tea intake Highest exposure: OR 0.59 (95% CI 0.34‐1.01) Liver cancer (Li 2011b) Intermediate exposure 1: OR 1.21 (95% CI 0.62‐2.36) Intermediate exposure 2: OR 0.76 (95% CI 0.38‐1.51) Highest exposure: OR 0.55 (95% CI 0.28‐1.09) Oesophageal cancer Intermediate exposure 1: OR 1.13 (95% CI 0.67‐1.92) Intermediate exposure 2: OR 0.78 (95% CI 0.46‐1.34) Highest exposure: OR 0.58 (95% CI 0.35‐0.97) |
Low risk: Li 2011b Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 8/9 stars, moderate quality. Mu 2003 Selection: 3/4 stars, potential selection bias for cases Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 7/9 stars, moderate quality. Mu 2005 Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 8/9 stars, moderate quality. |
| Nagle 2010 | Reference category: lowest exposure Ovarian cancer Intermediate exposure 1: OR 0.77 (95% CI 0.61‐0.98) Intermediate exposure 2: OR 0.85 (95% CI 0.63‐1.15) Intermediate exposure 3: OR 0.80 (95% CI 0.54‐1.19) Intermediate exposure 4: OR 0.92 (95% CI 0.57‐1.49) Highest exposure: OR 0.82 (95% CI 0.38‐1.79) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 8/9 stars, moderate quality |
| Oze 2014 | Reference category: lowest exposure Upper aerodigestive tract cancer Intermediate exposure 1: OR 1.25 (95% CI 0.98–1.60) Intermediate exposure 2: OR 1.02 (95% CI 0.77–1.34) Highest exposure: OR 1.39 (95% CI 1.13–1.70) Subsite Oesophageal cancer Intermediate exposure 1: OR 1.20 (95% CI 0.82–1.77) Intermediate exposure 2: OR 1.00 (95% CI 0.65–1.55) Highest exposure: OR 1.31 (95% CI 0.95–1.81) Oral, pharyngeal and laryngeal cancer Intermediate exposure 1: OR 1.34 (95% CI 0.97–1.86) Intermediate exposure 2: OR 1.03 (95% CI 0.71–1.50) Highest exposure: OR 1.47 (95% CI 1.12–1.93) Available also stratified analysis by smoking status (never, ever) and alcoholic drinker |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 8/9 stars, moderate quality. |
| Peng 2013 | Reference category: lowest exposure Colorectal cancer Highest exposure: OR 0.54 (95% CI 0.41‐0.72) |
Low risk: Selection: 4/4 stars, low risk Comparability: 1/2 stars, the study did not control for smoking. Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 7/9 stars, moderate quality |
| Peng 2015 | Reference category: lowest exposure Oesophageal cancer Highest exposure: OR 0.63 (95% CI 0.45‐0.91) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 8/9 stars, moderate quality. |
| Ruan 2010 | Reference category: lowest exposure Nasopharyngeal cancer Highest exposure: OR 0.44 (95% CI 0.36–0.54) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 1/2 stars, the study did not control for smoking Exposure: 3/3 stars, low risk Total score: 7/9 stars, moderate quality. |
| Setiawan 2001 | Reference category: lowest exposure Stomach cancer Exposure assessment A Highest exposure: OR 0.52 (95% CI 0.29–0.94) Exposure assessment B Intermediate exposure: OR 0.70 (95% CI 0.36–1.36) Highest exposure: OR 0.39 (95% CI 0.15–1.01) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 8/9 stars, moderate quality. |
| Shrubsole 2009 | Reference category: lowest exposure Breast cancer Exposure assessment A Highest exposure: OR 0.88 (95% CI 0.79–0.98) Exposure assessment B Intermediate exposure 1: OR 0.89 (95% CI 0.73–1.08) Intermediate exposure 2: OR 0.93 (95% CI 0.77–1.12) Intermediate exposure 3: OR 0.72 (95% CI 0.59–0.88) Highest exposure: OR 0.97 (95% CI 0.80–1.16) Stratified analysis also available in pre‐ and post‐menopausal women |
Low risk: Selection: 4/4 stars, low risk Comparability: 1/2 stars, the study did not control for smoking. Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 7/9 stars, moderate quality. |
| Song 2008 | Reference category: lowest exposure Ovarian cancer Intermediate category: OR 0.82 (95% CI 0.66‐1.04) Highest exposure: OR 0.46 (95% CI 0.26‐0.84) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 8/9 stars, moderate quality |
| Sonoda 2004 | Reference category: lowest exposure Prostate cancer Intermediate exposure 1: OR 0.99 (95% CI 0.48‐2.03) Intermediate exposure 2: OR 0.79 (95% CI 0.38‐1.63) Highest exposure: OR 0.67 (95% CI 0.27‐1.64) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 7/9 stars, moderate quality. |
| Tajima 1985 | Reference category: lowest exposure Stomach cancer Highest exposure: OR 0.64, CIs NR Colon cancer Highest exposure: OR 0.97, CIs NR Rectal cancer Highest exposure: OR 0.91, CIs NR |
High risk: Selection: 3/4 stars, hospital controls Comparability: 1/2 stars, the study did not control for smoking Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 6/9 stars, low quality. |
| Takezaki 2000 | Reference category: lowest exposure Pharynx (hypopharynx) cancer Intermediate exposure: OR 0.8 (95% CI 0.4‐1.5) Highest exposure: OR 0.8 (95% CI 0.3‐2.3) Oesophageal cancer Intermediate exposure: OR 0.8 (95% CI 0.6‐1.1) Highest exposure: OR 0.7 (95% CI 0.4‐1.2) Analysis also reported for upper, middle and lower third of the oesophagus |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 8/9 stars, moderate quality. |
| Takezaki 2001 | Reference category: lowest quartile Adenocarcinoma Men Intermediate exposure 1: OR 1.06 (95% CI 0.72‐1.57) Intermediate exposure 2: OR 1.11 (95% CI 0.74‐1.66) Highest exposure: OR 1.33 (95% CI 0.83‐2.15) Women Intermediate exposure 1: OR 0.98 (95% CI 0.58‐1.66) Intermediate exposure 2: OR 1.14 (95% CI 0.68‐1.93) Highest exposure: OR 1.14 (95% CI 0.61‐2.12) Squamous cell and small‐cell carcinoma Men Intermediate exposure 1: OR 0.99 (95% CI 0.67‐1.47) Intermediate exposure 2: OR 1.17 (95% CI 0.78‐1.73) Highest exposure: OR 1.08 (95% CI 0.66‐1.75) Women Intermediate exposure 1: OR 0.36 (95% CI 0.14‐0.93) Intermediate exposure 2: OR 0.41 (95% CI 0.16‐1.04) Highest exposure: OR 0.49 (95% CI 0.17‐1.46) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 8/9 stars, moderate quality. |
| Tewes 1990 | Reference category: lowest exposure Lung cancer Highest exposure: OR 2.74 (95% CI 1.10‐6.80) |
Low risk: Selection: 3/4 stars, case identification with no independent validation Comparability: 2/2 stars, low risk Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 7/9 stars, moderate quality. |
| Tse 2017 | Reference category: lowest exposure Prostate cancer Highest exposure: OR 0.56 (95% CI 0.34‐0.91) |
High risk: Selection: 3/4 stars, hospital controls Comparability: 1/2 stars, the study did not control for smoking. Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 6/9 stars, low quality. |
| Wakai 2004 | Reference category: lowest exposure Bladder cancer Intermediate exposure 1: OR 1.49 (95% CI 0.78–2.84) Intermediate exposure 2: OR 2.79 (95% CI 1.49–5.23) Highest exposure: OR 1.24 (95% CI 0.51–2.99) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 8/9 stars, moderate quality. |
| Wang 1999 | Reference category: lowest exposure Oesophageal cancer Highest exposure: OR 0.20 (95% CI 0.06‐0.67) Other stomach cancer Highest exposure: OR 0.28 (CIs NR) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 1/3 stars, no description of exposure ascertainment and non‐response rate different between cases and controls or NR Total score: 7/9 stars, moderate quality. |
| Wang 2006 | Reference category: lowest quartile Oesophageal cancer Highest exposure: OR 0.13 (95% CI 0.03‐0.62) |
High risk: Selection: 4/4 stars, low risk Comparability: 0/2 stars, no information on confounders as smoking Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 6/9 stars, low quality. |
| Wang 2007 | Reference category: lowest exposure Oesophageal cancer Men Highest exposure: OR 1.368 (95% CI 0.948‐1.975) Women Highest exposure: OR 0.257 (95% CI 0.070‐0.941) Available analysis according green tea drinking duration (years) |
Low risk: Selection: 4/4 stars, low risk Comparability: 1/2 stars, the study did not control for smoking. Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 7/9 stars, moderate quality. |
| Wang 2012a | Reference category: lowest exposure Renal cancer Highest exposure: OR 0.34 (95% CI 0.21–0.55) |
High risk: Selection: 3/4 stars, hospital controls Comparability: 1/2 stars, the study did not control for smoking. Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 6/9 stars, low quality. |
| Wang 2012b | Reference category: lowest exposure Multiple myeloma Intermediate exposure 1: OR 0.94 (95% CI 0.52–1.72) Intermediate exposure 2: OR 0.51 (95% CI 0.35‐0.73) Highest exposure: OR 0.27 (95% CI 0.13–0.58) Overall exposure: OR 0.38 (95% CI 0.27‐0.53) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 1/2 stars, the study did not control for smoking. Exposure: 3/3 stars, low risk Total score: 7/9 stars, moderate quality. |
| Wang 2012c | Reference category: lowest exposure Pancreatic cancer Men Exposure assessment A Highest exposure: OR 1.02 (95% CI 0.78‐1.35) Exposure assessment B Intermediate exposure 1: OR 0.99 (95% CI 0.71‐1.40) Intermediate exposure 2: OR 1.38 (95% CI 0.91‐2.11) Highest exposure: OR 0.91 (95% CI 0.65‐1.27) Women Exposure assessment A Highest exposure: OR 0.68 (95% CI 0.48‐0.96) Exposure assessment B Intermediate exposure 1: OR 0.85 (95% CI 0.49–1.46) Intermediate exposure 2: OR 0.64 (95% CI 0.37‐1.11) Highest exposure: OR 0.56 (95% CI 0.32‐0.98) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 8/9 stars, moderate quality. |
| Wang 2013a | Reference category: lowest exposure Breast cancer Highest exposure: OR 0.65 (95% CI 0.44–0.97) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 1/2 stars, the study did not control for smoking. Exposure: 3/3 stars, low risk Total score: 7/9 stars, moderate quality. |
| Wang 2013b | Reference category: lowest exposure Bladder cancer Intermediate exposure: OR 0.82 (95% CI 0.61–1.11) Highest exposure: OR 0.60 (95% CI 0.45–0.79) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 7/9 stars, moderate quality. |
| Wang 2015 | Reference category: lowest exposure Stomach cancer Exposure assessment A: green tea intake Highest exposure: OR 0.72 (95% CI 0.32‐0.98) Exposure assessment B: green tea consumption Intermediate exposure: OR 0.87 (95% CI 0.43‐1.81) Intermediate exposure: OR 0.66 (95% CI 0.36‐1.17) Highest exposure: OR 0.53 (95% CI 0.23‐0.97) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or not reported Total score: 7/9 stars, moderate quality. |
| Wilkens 1996 | Reference category: lowest exposure Urinary tract cancer Men Intermediate exposure: OR 1.1 (95% CI 0.6‐1.9) Highest exposure: OR 1.1 (95% CI 0.6‐2.3) Women Intermediate exposure: OR 0.8 (95% CI 0.3‐2.1) Highest exposure: OR 0.9 (95% CI 0.3‐2.6) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 8/9 stars, moderate quality. |
| Wu 2003 | Reference category: lowest exposure Breast cancer Intermediate exposure: OR 0.74 (95% CI 0.52‐1.04) Highest exposure: OR 0.61 (95% CI 0.40‐0.93) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 9/9 stars, high quality. |
| Wu 2009a | Reference category: lowest exposure Prostate cancer Highest exposure: OR 0.52 (95% CI 0.28‐0.96) Intermediate categories NR |
High risk: Selection: 2/4 stars, potential selection bias for cases and hospital controls Comparability: 1/2 stars, the study did not control for smoking. Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 5/9 stars, low quality. |
| Wu 2009b | Reference category: lowest exposure Oesophageal cancer Dafeng (high risk area) Highest exposure: OR 1.0 (95% CI 0.7‐1.3) Ganyu (low risk area) Highest exposure: OR 1.3 (95% CI 0.9‐1.7) |
Low risk: Selection: 3/4 stars, potential for selection bias in cases Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 8/9 stars, moderate quality. |
| Xu 2007 | Reference category: lowest exposure Endometrial cancer Highest exposure: OR 0.8 (95% CI 0.6‐0.9) |
Low risk: Selection: 4/4 stars, low risk Comparability: 1/2 stars, the study did not control for smoking. Exposure: 3/3 stars, low risk Total score: 8/9 stars, moderate quality. |
| Xu 2013 | Reference category: lowest exposure Lung cancer Highest exposure: OR 0.333 (95% CI 0.154 ‐0.720) |
High risk: Selection: 1/4 star, no description of cases, potential selection bias in cases, no description of controls Comparability: 1/2 stars, the study did not control for smoking. Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 4/9 stars, low quality. |
| Yan 2016 | Reference category: lowest exposure Oral cancer Highest exposure: OR 0.58 (95% CI 0.42‐0.79) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 8/9 stars, moderate quality. |
| Ye 1998 | Reference category: lowest exposure Stomach cancer Highest exposure: OR 1.72 (95% CI 1.26‐2.36) |
Low risk: Selection: 4/4 stars, low risk Comparability: 1/2 stars, the study did not control for smoking. Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 7/9 stars, moderate quality. |
| Yu 1995 | Reference category: lowest exposure Stomach cancer Highest exposure: OR 0.71 (95% CI 0.54‐0.93) Highest exposure A: OR 0.76 (95% CI 0.57‐1.03) Highest exposure B: OR 0.54 (95% CI 0.33‐0.88) Subsite Cardia Highest exposure: OR 0.95 (95% CI 0.51‐1.77) Highest exposure A: OR 0.94 (95% CI 0.47‐1.87) Highest exposure B: OR 0.98 (95% CI 0.34‐2.89) Pylori Highest exposure: OR 0.29 (95% CI 0.13‐0.68) Highest exposure A: OR 0.30 (95% CI 0.13‐0.73) Highest exposure B: OR 0.24 (95% CI 0.05‐1.17) Antrum Highest exposure: OR 0.67 (95% CI 0.41‐1.08) Highest exposure A: OR 0.79 (95% CI 0.48‐1.31) Highest exposure B: OR 0.29 (95% CI 0.12‐0.71) Other sites Highest exposure: OR 0.82 (95% CI 0.41‐1.65) Highest exposure A: OR 0.83 (95% CI 0.40‐1.73) Highest exposure B: OR 0.76 (95% CI 0.15‐3.87) Site unknown Highest exposure: OR 0.69 (95% CI 0.23‐2.06) Highest exposure A: OR 0.62 (95% CI 0.17‐2.18) Highest exposure B: OR 0.87 (95% CI 0.15‐5.00) |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 8/9 stars, moderate quality. |
| Zhang 2002 | Reference category: lowest exposure Ovarian cancer Intermediate exposure 1: OR 0.42 (95% CI 0.24‐0.73) Intermediate exposure 2: OR 0.40 (95% CI 0.23‐0.70) Highest exposure: OR= 0.43 (95% CI 0.30‐0.63) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 7/9 stars, moderate quality. |
| Zhang 2007 | Reference category: lowest exposure Breast cancer Intermediate exposure 1: 0.85 (95% CI 0.68–1.05) Intermediate exposure 2: 0.92 (95% CI 0.75–1.12) Intermediate exposure 3: 0.57 (95% CI 0.38–0.85) Highest exposure: 0.57 (95% CI 0.47–0.69) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 3/3 stars, low risk Total score: 8/9 stars, moderate quality. |
| Zhang 2008 | Reference category: lowest exposure Leukaemia Exposure assessment A: intake of green tea Highest exposure: OR 0.51 (95% CI 0.27–0.96) Exposure assessment B: intake of green tea Intermediate exposure: OR 0.40 (95% CI 0.14–1.14) Highest exposure: OR 0.40 (95% CI 0.19–0.82) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire. Total score: 7/9 stars, moderate quality. |
| Zheng 1993 | Reference category: lowest exposure Oral cancer Highest exposure: HR 0.85 (95% CI 0.32–2.31) |
Low risk: Selection: 3/4 stars, hospital controls Comparability: 2/2 stars, low risk Exposure: 2/3 stars, self‐reported exposure not within a structured interview or questionnaire Total score: 7/9 stars, moderate quality. |
| Zhong 2001 | Reference category: lowest exposure Lung cancer Highest exposure: OR 0.65 (95% CI 0.45‐0.93) in nonsmokers Highest exposure: OR 0.94 (95% CI 0.40‐2.22) in smokers |
Low risk: Selection: 4/4 stars, low risk Comparability: 2/2 stars, low risk Exposure: 2/3 stars, non‐response rate different between cases and controls or NR Total score: 8/9 stars, moderate quality. |