Dietary factors
|
| Fruit, vegetables | 20 CC 11 COH | Fruit and vegetables; high versus low | Yes | RR 0.81; 95 % CI 0.67–0.99 | 10 | Smoking | I2 = 58.4 % | |
| | | Fruit; high versus low | Yes | RR 0.77; 95 % CI 0.69–0.87 | 27 | Smoking | I2 = 54.9 % | Egger p = 0.003 |
| | | Vegetables; high versus low | Yes (MMA) | RR 0.81; 95 % CI 0.70–0.93 | 21 | Smoking | I2 = 66.0 % | Egger p = 0.389 |
| | | Citrus Fruits; high versus low | No | RR 0.79; 95 % CI 0.68–0.91 | 11 | | I2 = 53.2 % | Egger p = 0.034 |
| | | Cruciferous vegetables; high versus low | Yes | RR 0.84; 95 % CI 0.77–0.91 | 11 | | I2 = 30.7 % | Egger p = 0.443 |
| Fruit (low intake) | 38 CC and COH | Fruits; low versus high | No | RR 1.47; 95 % CI 1.25–1.74 | 8 | Smoking | X2
p = 0.99$
| |
| Vegetables (low intake) | | Vegetables; low versus high | Yes (MMA) | RR 1.15; 95 % CI 0.98–1.35 | 8 | Smoking | X2
p = 0.82$
| |
| Meat | | High versus low | No | RR 0.96; 95 % CI 0.73–1.27 | 4 | Smoking | X2
p = 0.97$
| |
| Vitamin A | | Retinol; low versus high intake | No | RR 1.01; 95 % CI 0.90–1.14 | 8 | | X2
p = 0.99$
| |
| Carotinoids | | Carotenoids; low versus high intake | No | RR 1.10; 95 % CI 0.99–1.22 | 3 | | X2
p = 0.99$
| |
| Fruit, Vegetables | 15 COH | Fruit and vegetables; high versus low | No | RR 0.89; 95 % CI 0.75–1.05 | 8 | | I2 = 33.8 % | |
| | | Fruit; high versus low | No | RRs = 0.91; 95 % CI 0.82–1.00 | 11 | Smoking | I2 = 11.0 % | Egger p = 0.48 |
| | | Vegetables; high versus low | No | RRs = 0.92; 95 % CI 0.84–1.01 | 9 | Smoking | I2 = 5.0 % | Egger p = 0.02 |
| | | Citrus fruit; high versus low | No | RRs = 0.88; 95 % CI 0.77–1.01 | 6 | Smoking | I2 = 0.0 % | Egger p = 0.38 |
| | | Cruciferous vegetables; high versus low | No | RRs = 0.85; 95 % CI 0.69–1.06 | 6 | Smoking | I2 = 62.6 % | Egger p = 0.5 |
| Fruit, vegetables | 15 CC 12 COH | Fruit and vegetables; high versus low | No | RR 0.83; 95 % CI 0.69–1.01 | 9 | | I2 = 57.0 % | |
| | | Fruit; high versus low | No | RR 0.81; 95 % CI 0.73–0.89 | 27 | | I2 = 53.7 % | Egger p = 0.052 |
| | | Vegetables; high versus low | No | RR 0.84; 95 % CI 0.72–0.96 | 24 | | I2 = 76.3 % | Egger p = 0.74 |
| Fruit, vegetables | 14 COH | Fruit and vegetables; every 0.2 serving increment per day | No | RR 1.00; 95 % CI 0.99–1.00 | 8 | | I2 = 38.5 % | |
| | | Fruit; every 0.2 serving increment per day | No | RRs = 1.00; 95 % CI 0.99–1.00 | 14 | Smoking | I2 = 45.8 % | Egger p < 0.01 |
| | | Vegetables; every 0.2 serving increment per day | No | RRs = 1.00; 95 % CI 0.99–1.00 | 14 | Smoking | I2 = 19.0 % | Egger p = 0.93 |
| | | Citrus fruit; every 0.2 serving increment per day | No | RRs = 1.00; 95 % CI 1.00–1.00 | 7 | | I2 = 0.0 % | |
| | | Cruciferous vegetables; every 0.2 serving increment per day | No | RRs = 0.97; 95 % CI 0.93–1.01 | 8 | | I2 = 55.8 % | |
| Citrus fruits | 8 CC 6 COH | Citrus fruits; high versus low | Yes | RR 0.85; 95 % CI 0.76–0.94 | 14 | | I2 = 72.1 % | Egger p = 0.004 |
| | 6 COH | Citrus fruits; high versus low | No | RR 0.96; 95 % CI 0.87–1.07 | 6 | | I2 = 19.8 % | |
| | 8 CC | Citrus fruits; high versus low | No | RR 0.77; 95 % CI 0.64–0.92 | 8 | | I2 = 68.7 % | |
| Cruciferous vegetables | 5 CC 5 COH | Cruciferous vegetables; high versus low | No | RR 0.80; 95 % CI 0.69–0.92 | 10 | | I2 = 45.9 % | Egger p = 0.51 |
| | 5 COH | Cruciferous vegetables; high versus low | No | Cohort: RR 0.86; 95 % CI 0.61–1.11 | 5 | | I2 = 73 % | |
| | 5 CC | Cruciferous vegetables; high versus low | No | CC: RR 0.78; 95 % CI 0.67–0.89 | 5 | | I2 = 0.0 % | |
| Total fluid intake | 17 CC 4 COH | High versus low | Yes | RRm = 1.12; 95 % CI 0.94–1.33 | 14 | Most adjusted | I2 = 82.8 % | Egger p = 0.059 |
Isa (submitted) | Total fluid intake | 15 CC 3 COH | 250 ml/day increment | No | RR 1.02; 95 % CI 1.00–1.04 | 15 | | | Egger p = 0.614 |
| Tea | 7 COH | All tea; high versus low | No | RR 0.92; 95 % CI 0.76–1.13 | 7 | | I2 = 23.8 % | |
| | | All tea; one cup/day increment | No | RR 0.98; 95 % CI 0.93–1.02 | 7 | | I2 = 44.1 % | |
| | | Green tea; one cup/day increment | No | RR 1.02; 95 % CI 0.95–1.11 | 3 | | I2 = 63.9 % | |
| | | Black tea; one cup/day increment | No | RR 0.73; 95 % CI 0.33–1.60 | 1 | | | |
| Tea | 12 CC 3 COH | All tea; high versus low | No | RRm = 1.01; 95 % CI 0.80–1.29 | 7 | Most adjusted | | Egger p = 0.88 |
| | | Green tea; high versus low | No | RR 1.03; 95 % CI 0.82–1.31 | 5 | | I2 = 0.0 % | Egger p = 0.49 |
| | | Black tea; high versus low | No | RR 0.84; 95 % CI 0.7–1.01 | 6 | | I2 = 0.0 % | Egger p = 1.0 |
| Tea | 13 CC 4 COH | All tea; high versus low | No | RRm = 1.12; 95 % CI 0.88–1.43; I2 = 64.6 %; n = 17 | 17 | Most adjusted | | Egger p = 0.298 |
| | | Green tea; high versus low | No | RR 0.81; 95 % CI 0.68–0.98 | 4 | | I2 = 0.0 % | Egger p = 0.73 |
| | | Black tea; high versus low | No | RR 1.05; 95 % CI 0.83–1.32 | 5 | | I2 = 49.4 % | Egger p = 0.41 |
| Tea | 17 CC 6 COH | All tea; high versus low | Yes | RR 0.94; 95 % CI 0.85–1.04 | 23 | | I2 = 28.3 % | Egger p = 0.52 |
| | | Green tea; high versus low | No | RR 0.97; 95 % CI 0.73–1.21; | 5 | | I2 = 0.0 % | Egger p = 0.38 |
| | | Black tea; high versus low | No | RR 0.79; 95 % CI 0.59–0.99 | 7 | | I2 = 33.1 % | Egger p = 0.38 |
| Coffee | 5 COH | High versus none/low | No | RR 1.08; 95 % CI 0.71–1.66 | 5 | | I2 = 62.9 % | |
| Coffee | 20 CC 5 COH | High (>5–6 cups/day) versus none | No | Case–control: RRs = 1.45; 95 % CI 1.29–1.63 This category was not calculated for cohort studies | 20 | | I2 = 31.8 % | No publication bias (no test estimate reported) |
| Coffee | Pooled analysis of 10 CC | 6–9 cups versus none | No | RRm = 1.0; 95 % CI 0.6–1.4 | | Most adjusted, analysis restricted to non-smokers | | |
| | | ≥10 cups versus none | No | RRm = 1.8; 95 % CI 1.0–3.3 | | Most adjusted, analysis restricted to non-smokers | | |
| Coffee | Pooled analysis of 6 CC | >5 cups/day versus ≤5 cups/day; overall | Yes (MMA) | RRms = 1.25; 95 % CI 1.08–1.44 | 6 | Most adjusted, incl. smoking | | |
| | | >5 cups/day versus ≤5 cups/day; men only | No | RRms = 1.23; 95 % CI 1.05–1.44 | 5 | Most adjusted, incl. smoking | | |
| | | >5 cups/day versus ≤5 cups/day; women only | No | RRms = 1.31; 95 % CI 0.99–1.74 | 5 | Most adjusted, incl. smoking | | |
| | | 1 l/day increment | No | RRms = 1.24; 95 % CI 1.08–1.43 | 6 | Most adjusted, incl. smoking | | |
| Coffee | 9 COH | Drinkers versus none/lowest | Yes (MMA) | RR 0.83; 95 % CI 0.73–0.94 | 9 | | I2 = 39.3 % | Egger p = 0.793 |
| Coffee | 34 CC 6 COH | High versus low | Yes (MMA) | RRms = 1.28; 95 % CI 1.21–1.46 | 18 | Most adjusted, incl. smoking | I2 = 28.5 | Egger p = 0.051 |
| Sweetened carbonated beverages | 5 studies | High versus low | Yes | RR 1.13; 95 % CI 0.89–1.45 | 5 | | I2 = 0.0 % | Egger p = 0.05 |
| Milk Dairy products | 12 CC 6 COH | Milk; high versus low | Yes | RRm = 0.91; 95 % CI 0.72–1.15 | 7 | Most adjusted | Q p = 0.020 | Egger p = 0.048 |
| | | Dairy products; high versus low | Yes | RRm = 1.01; 95 % CI 0.86–1.19 | 3 | Most adjusted | Q p = 0.108 | Egger p = 0.73 |
| Milk and Dairy products | 8 HCC 5 PCC 6 COH | All milk; high versus low | No | RRms = 0.84; 95 % CI 0.72–0.97 | 16 | Most adjusted, incl. smoking | I2 = 70.1 % | Egger p = 0.055 |
| | | Whole milk; high versus low | No | RR 2.23; 95 % CI 1.45–3.00 | 2 | | I2 = 0 | |
| | | Skim milk; high versus low | No | RR 0.47; 95 % CI 0.18–0.79 | 2 | | I2 = 0 | |
| | | Fermented milk; high versus low | No | RR 0.69; 95 % CI 0.47–0.91 | 5 | | I2 = 62.5 % | |
| Fish | 6 HCC 3 PCC 5 COH | High versus low | Yes | RRs = 0.86; 95 % CI 0.61–1.12; I2 = 85.4 %; n = 14; Begg’s p = 0.101 | 14 | Smoking | | |
| Meat | 9 CC 5 COH | Red meat; high versus low | Yes | RR 1.15; 95 % CI 0.97–1.36 | 14 | | I2 = 73.5 % | Egger p = 0.83 |
| | 6 CC 5 COH | Processed meat; high versus low | Yes | RR 1.22; 95 % CI 1.04–1.43 | 11 | | I2 = 64.9 % | Egger p = 0.35 |
| Alcohol | 14 CC 2 NCC 3 COH | Heavy intake, ≥ 3 drinks (≥ 37.5 g)/day versus non-drinkers | Yes | RR 0.97; 95 % CI 0.72–1.31 | 7 | Smoking | X2
p < 0.01 | |
| | | Moderate intake, <3 drinks/day versus non-drinkers | No | RR 0.98; 95 % CI 0.89–1.07 | 15 | Smoking | X2
p = 0.05 | |
| Alcohol | 9 CC 2 COH | Highest category (100 g/day) versus non-drinkers | No | RR 1.17; 95 % CI: 0.97–1.41 | 11 | | Het. p = N.S. | |
| | | Highest category (100 g/day) versus non-drinkers | No | RRs = 1.09; 95 % CI: 0.89–1.33 | | Smoking | Het. p < 0.05 | |
| Alcohol | 6 studies | Current alcohol use versus non-use | No | RR 1.3; 95 % CI 1.1–1.5 | 6 | | | |
| Egg | 9 CC 4 COH | All eggs; high versus low | Yes | RRm = 1.11; 95 % CI 0.73–1.69 | 6 | Most adjusted | I2 = 75.8 % | Egger p = 0.55 |
| | | Fried eggs; high versus low | No | RR 2.04; 95 % CI 1.41–2.95 | 2 | | I2 = 0.0 % | |
| | | Boiled eggs; high versus low | No | RR 1.25; 95 % CI 0.82–1.91 | 2 | | I2 = 35.5 % | |
| Dietary acrylamide | 1 CC 1 COH 1 C-COH | High versus low | Yes | RR 0.93; 95 % CI 0.78–1.11 | 3 | | X2
p = 0.91 | |
| | | 10 mg/day increase in intake | No | RR 1.00; 95 % CI 0.96–1.03 | 3 | | X2
p = 0.97 | |
| Vitamin A (total) | 14 CC 11 COH | Supplement, diet and blood levels; high versus low | Yes | RRms = 0.82; 95 % CI 0.65–0.95 | 11 | Most adjusted, incl. smoking | I2 = 46.3 % | Egger p = 0.057 |
| | | Dietary intake; high versus low | No | RRms = 0.90; 95 % CI 0.80–1.01 | | Most adjusted, incl. smoking | I2 = 0 % | |
| | | Supplementation versus placebo or no supplementation | Yes | RRms = 0.64; 95 % CI 0.47–0.82 | | Most adjusted, incl. smoking | I2 = 0 % | |
| Beta-carotene supplements | 2 RCT | Supplementation versus placebo or no supplementation | No | RR 1.52; 95 % CI 1.03–2.24 | 2 | | I2 = 0.0 % | |
| Vitamin D | 1 CC 2 NCC 2 COH | Serum levels; high versus low | Yes | RRs = 0.75; 95 % CI 0.65–0.87 | 5 | Smoking | I2 = 0.0 % | Egger p = 0.57 |
| Vitamin D | 1 CC 3 COH | Circulating levels; high versus low | No | RR 0.75; 95 % CI 0.57–0.99 | 4 | | I2 = 51.7 % | Egger p = 0.87 |
| | 3 studies | Diet and supplement; high versus low | No | RR 0.92; 95 % CI 0.66–1.28 | 3 | | I2 = 32.3 % | Egger p = 0.41 |
| Vitamin E | 4 CC 5 COH | Diet; high versus low | No | RRm = 0.69; 95 % CI 0.52–0.92 | 5 | | I2 = 47.1 % | Egger p = 0.01 |
| | 3 CC 3 COH | Diet and supplement; high versus low | No | RRm = 0.76; 95 % CI 0.56–1.02 | 5 | | I2 = 49.8 % | Egger p = 0.35 |
| | 1 CC 6 COH | Supplementation versus placebo or no supplementation | No | RRm = 0.64; 95 % CI 0.48–0.85 | | | I2 = 0.6 % | Egger p = 0.39 |
| Vitamin C | 7 CC 7 COH | Diet; High versus Low | No | RRm = 0.69; 95 % CI 0.58–0.82 | 6 | | I2 = 13.7 % | Egger p = 0.28 |
| | 5 CC 3 COH | Diet and supplement; high versus low | No | RRm = 0.80; 95 % CI 0.62–1.03 | 5 | | I2 = 33.4 % | Egger p = 0.03 |
| | 6 CC 3 COH | Supplementation versus placebo or no supplementation | No | RRm = 0.84; 95 % CI 0.55–1.29 | 4 | | I2 = 74.4 % | Egger p = 0.002 |
| Vitamin C | 11 CC 9 COH | Intake; high versus low | Yes | RRs = 0.90; 95 % CI 0.79–1.00 | 20 | Smoking | I2 = 43.7 % | Egger p = 0.064 |
| Vitamin E | 7 CC 8 COH | Intake; high versus low | Yes | RRs = 0.82; 95 % CI 0.74–0.90 | 15 | Smoking | I2 = 0 % | Egger p = 0.534 |
| Folate | 6 CC 7 COH | Intake; high versus low | Yes | RR 0.84; 95 % CI 0.72–0.96 | 13 | | I2 = 28.9 % | Egger p = 0.06 |
| Antioxidant supplement | 4 RCT | Supplementation versus placebo or no supplementation | No | RR 1.52; 95 % CI 1.06–2.17 | 4 | | I2 = 0.0 % | |
| Selenium | 3 CC 3 NCC 1 C-COH | Serum and toenail levels; high versus low | Yes | OR = 0.61; 95 % CI 0.42–0.87 | 7 | | I2 = 60.8 % | Egger p = 0.357 |
Vinceti et al. [ 43] (Cochrane SR) | Selenium | 5 prospective studies | Serum, toenail or plasma levels; high versus low | No | OR = 0.67; 95 % CI 0.46–0.97 | 5 | | I2 = 30 % | |
| | 2 RCT | Supplementation versus Placebo | Yes | RR 1.14; 95 % CI 0.81–1.61 | 2 | | I2 = 0.0 % | |
| Obesity | 15 COH | Obese versus normal weight | Yes | RRs = 1.10; 95 % CI 1.03–1.18 | 12 | Smoking | I2 = 8.8 % | Egger p = 0.712 |
| | | Pre-obese versus normal weight | Yes | RRs = 1.07; 95 % CI 0.99–1.16 | 13 | Smoking | I2 = 46.1 % | Egger p = 0.712 |
| Obesity | 11 COH | Obese versus normal weight | No | RRs = 1.09; 95 % CI 1.01–1.17 | 9 | Smoking | I2 = 35.9 % | Egger p = 0.244 |
Behavioural factors
|
| Smoking | 21 CC 11 COH 2 NCC | All tobacco; Ever smokers versus never smokers | No | RR 2.25; 95 % CI 1.96–2.59 | 15 | | | |
| | | All tobacco; Ex smokers versus never smokers | No | RR 1.90; 95 % CI 1.71–2.11 | 8 | | | |
| | | All tobacco; Current smokers versus never smokers | No | RR 3.35; 95 % CI 2.90–3.88 | 11 | | | |
| | | Cigarettes; Ever smokers versus never smokers | No | RR 2.24; 95 % CI 1.81–2.78 | 9 | | | |
| | | Cigarettes; Ex smokers versus never smokers | No | RR 1.95; 95 % CI 1.55–2.47 | 4 | | | |
| | | Cigarettes; Current smokers versus never smokers | No | RR 3.13; 95 % CI 2.33–4.21 | 6 | | | |
| Smoking | Pooled analysis of 14 CC | Current smokers versus never smokers; Male | No | RR 3.89; 95 % CI 3.53–4.29 | | | | |
| | | Current smokers versus never smokers; Female | No | RR 3.55; 95 % CI 3.06–4.10 | | | | |
| | | Ex-smokers versus never smokers; Male | No | RR 2.21; 95 % CI 2.01–2.43 | | | | |
| | | Ex-smokers versus never smokers; Female | No | RR 2.21; 95 % CI 1.87–2.61 | | | | |
| Smoking | 7 COH | Current smokers versus never smokers | No | RR 2.94; 95 % CI 2.45–3.54 | 7 | | I2 = 0.0 % | Egger p = 0.32 |
| Smoking | Pooled analysis of 11 CC (men only) | Ever-smokers versus never smokers | No | RR 3.63; 95 % CI 3.13–4.20 | | | | |
| | | Current smokers versus never and ex-smokers | No | RR 2.47; 95 % CI 2.23–2.74 | | | | |
| Smoking | Pooled analysis of 11 CC (women only) | Ever-smokers versus never smokers | No | RR 3.1; 95 % CI 2.5–3.9 | | | | |
| | | Current smokers versus never and ex-smokers | No | RR 2.9; 95 % CI 2.3–3.7 | | | | |
Van Osch et al. submitted [ 10] | Active smoking | 18 COH 71 CC | Active smoking; Ex-smokers versus never smokers | Yes | RR 1.83; 95 % CI 1.52–2.14 | 12 | Age, sex | | Egger p = 0.150 |
| | | Active smoking; Current smokers versus never smokers | Yes | RR 3.14; 95 % CI 2.53–3.75 | 13 | Age, sex | | |
| | | Active smoking; ≤20 versus >20 years at first exposure | No | RR 1.33; 95 % CI 0.92–1.74 | 4 | | | |
| Active smoking | | Ex-smokers versus never smokers | No | RR 3.37; 95 % CI 3.01–3.78 | 48 | Most adjusted estimates in MA | I2 = 82.2 % | Egger p = 0.13 Begg p = 0.03 |
| | | Current smokers versus never smokers | No | RR 1.98; 95 % CI 1.76–2.22 | 49 | Most adjusted estimates in MA | I2 = 78.6 % | |
| | | Pipe; Smokers versus never smokers | No | RR 1.49; 95 % CI 1.18–1.88 | 4 | | I2 = 39.4 % | |
| | | Cigar; Smokers versus never smokers | No | RR 1.62; 95 % CI 1.18–2.22 | 4 | | I2 = 0.0 % | |
| Smokeless tobacco | | Snuff; users versus non-users | No | RR 0.89; 95 % CI 0.56–1.42 | 2 | | I2 = 23.7 % | |
| | | Chewing tobacco; users versus non-users | No | RR 1.04; 95 % CI 0.75–1.45 | 2 | | I2 = 0.0 % | |
| Active smoking | Pooled analysis of 6 CC (men only) | Pipe only; Smokers versus never smokers | Yes | RR 1.9; 95 % CI 1.2–3.1 | | | | |
| | | Cigar only; Smokers versus never smokers | Yes | RR 2.3; 95 % CI 1.6–3.5 | | | | |
| | | Cigarette only; Smokers versus never smokers | No | RR 3.5; 95 % CI 2.9–4.2 | | | | |
Van Hemelrijck et al. [ 54] | Passive smoking | 5 CC 3 COH | Exposed versus not exposed | Yes | RR 0.99; 95 % CI 0.86–1.14 | 8 | Non-smokers only | I2 = 35.6 % | Begg p = 0.32 |
| Smokeless tobacco | 12 CC 1 COH | Smokeless tobacco use versus never use | Yes | RRs = 0.95; 95 % CI 0.71–1.29 | 9 | Smoking | I2 = 59.6 % | |
| Physical activity | 4 CC 11 COH | High versus low | Yes | RRm = 0.86; 95 % CI 0.77–0.95 | 7 | Most adjusted | I2 = 0.0 % | |
| Personal hair dye | 15 CC 2 COH | Personal use of any type of hair dyes versus no use | Yes | RRs = 0.94; 95 % CI 0.82–1.08 | 12 | Smoking | I2 = 49.9 % | Egger p = 0.54 |
Occupational (Comparing the specific occupation versus any other occupation or the general population) | | | | | | | | | |
| Painters | 30 CC 2 COH 9 RL | Painters | No | RR 1.25; 95 % CI 1.16–1.34 | 41 | | I2 = 23.5 % | |
| | | Painters | No | RRs = 1.28; 95 % CI 1.15–1.43 | | Smoking | I2 = 0.7 % | |
| | | Painters | No | RRms = 1.27; 95 % CI 0.99–1.63 | | Most adjusted, incl. smoking | I2 = 0.1 % | |
| Painters | 33 CC | Painters | No | RR 1.30; 95 % CI 1.17–1.44 | 33 | Smoking; morbidity and mortality combined | | |
| | 4 COH | Painters | No | RR 1.23; 95 % CI 0.95–1.59 | 4 | Smoking; morbidity only | | |
| Hairdressers | 28 CC 14 RCOH | Hairdressers | No | RR 1.35; 95 % CI 1.13–1.61 | 23 | Smoking | X2
p = 0.19 | |
| | | Hairdressers; job held ≥ 10 years | No | RR 1.70; 95 % CI 1.01–2.88 | 6 | | X2
p = 0.46 | |
| Hairdressers | 26 CC 8 COH | Hairdressers | No | RR 1.33; 95 % CI 1.07–1.67 | 19 | Smoking | Q p = 0.77 | |
| | | Hairdressers | No | RR 1.35; 95 % CI 1.21–1.50 | 26 | Incidence only | Q p = 0.78 | |
| Sales workers | 10 CC 2 RL 3 mortality studies | Sales workers; Men | No | RR 1.04; 95 % CI 0.97–1.12 | | Smoking, incidence only | Q p = 0.3 | Egger p = 0.4 |
| | | Sales workers; Women | No | RR 1.22; 95 % CI 1.06–1.41 | | Smoking, incidence only | Q p = 0.44 | Egger p < 0.01 |
| Motor vehicle driving | 3 COH | Overall (motor vehicle drivers and railroad workers) | No | RR 1.08; 95 % CI 1.00–1.17 | 3 | | Het. p = 0.85 | |
| | 27 CC | Truck drivers | No | RR 1.18; 95 % CI 1.09–1.28 | 18 | | Het. p = 0.25 | |
| | 27 CC | Bus drivers | No | RR 1.23; 95 % CI 1.06–1.44 | 11 | | Het. p = 0.19 | |
Boffetta and Silverman [ 163] | Motor vehicle driving | 16 CC 7 COH 6 routinely collected data (men only) | Truck drivers | No | RR 1.17; 95 % CI 1.06–1.29 | 15 | | Het. p = 0.3 | Egger p = 0.07 |
| | | Bus drivers | No | RR 1.33; 95 % CI 1.22–1.45 | 10 | | Het. p = 0.4 | Egger p = 0.001 |
| Farmers | 10 Follow-up studies 8 CC 11 PMR (men only) | Farmers | No | RR 0.79; 95 % CI 0.72–0.86 | 29 | | X2
p < 1*10−5
| |
| | 10 Follow-up studies | Farmers | No | RR 0.62; 95 % CI 0.59–0.65 | 10 | | X2
p = 0.08 | |
| | 8 CC | Farmers | No | RR 0.94; 95 % CI 0.86–1.04 | 8 | | X2
p = 0.09 | |
| Foundry workers | 22 CC 9 COH 14 surveillance studies | Foundry workers | No | RR 1.11; 95 % CI 0.96–1.29 | 16 (CC only) | Smoking | X2
p = 0.07 (15df) | |
| | | Foundry workers | No | RR 1.14; 95 % CI 1.04–1.26; | 11 | Incidence only | X2
p = 0.28 (10df) | |
| Textile workers | Unknown | Spinners | No | RR 1.19; 95 % CI 0.80–1.57 | 2 | | X2
p < 0.001$
| |
| | | Weavers | No | RR 2.40; 95 % CI 1.62–3.18 | 2 | | X2
p = 0.001$
| |
| | | Dyers | No | RR 1.39; 95 % CI 1.07–1.71 | 3 | | X2
p = 0.505$
| |
| Flight attendants | 3 COH (female only) | Flight attendants | No | RR 2.03; 95 % CI 0.75–5.43 | 3 | Incidence only | Q p = N.S. | |
| Flight attendants | 4 COH (female only) | Flight attendants | No | RR 1.45; 95 % CI 0.33–3.16 | 4 | Incidence only | Tau = 0.39 | |
| Petroleum industry | 8 CC | Petroleum industry workers | No | RR 1.5; 95 % CI 1.29–1.75 | 8 | | | |
| Chemical workers | 19 COH for incidence | Chemical workers | No | RR 2.21; 95 % CI 1.18–4.15 | 19 | Incidence only | | |
| Dry cleaning | 4 CC 3 COH | Dry cleaning workers | No | RR 1.47; 95 % CI 1.16–1.85 | 7 | | I2 = 0 % | Egger p > 0.05 |
| Inorganic lead compounds | 5 studies | Exposed to inorganic lead compounds versus non-exposed | No | RR 1.41; 95 % CI 1.16–1.71 | 5 | | Hom. p > 0.30 | |
| Acrylonitrile workers | 10 studies | Acrylonitrile workers | No | RR 0.8; 95 % CI 0.3–2.2 | 3 | Incidence | Het. p = 0.49 | |
| Polycyclic aromatic hydrocarbons (PAHs) | 13 COH | Aluminium production workers | No | RR 1.28; 95 % CI 0.98–1.68 | 10 | | X2
p = 0.002 | Egger p = 0.22 |
| | | Asphalt workers | No | RR 1.03; 95 % CI 0.82–1.30 | 2 | | X2
p = 0.31 | |
| | | Carbon black production | No | RR 1.10; 95 % CI 0.61–2.00 | 3 | | X2
p = 0.29 | Egger p = 0.61 |
| | | Workers in iron and steel foundry | No | RR 1.38; 95 % CI 1.00–1.91 | 9 | | X2
p = 0.001 | Egger p = 0.3 |