Table 2.
Adjusted odds ratios and 95% confidence intervals of bladder cancer according to coffee consumption level stratified by smoking
| Study sub-groups | Model adjustments | Coffee consumption (ORs and 95% CI) | p trend | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Never | Ever | ≤ 1 cups/day | 1–2 cups/day | 2–3 cups/day | 3–4 cups/day | > 4 cups/day | |||
| Overall (n = 22,083) | Model 1a | Reference | 1.42 (1.26–1.59) | 1.05 (0.91–1.22) | 1.35 (1.17–1.55) | 1.23 (1.06–1.42) | 1.51 (1.31–1.76) | 1.82 (1.60–2.07) | 0.04 |
| Model 2b | Reference | 1.11 (0.98–1.26) | 0.94 (0.80–1.10) | 1.12 (0.96–1.29) | 1.01 (0.86–1.17) | 1.16 (0.99–1.35) | 1.27 (1.11–1.46) | 0.05 | |
| Model 3c | Reference | 1.09 (0.94–1.25) | 0.92 (0.77–1.10) | 1.04 (0.88–1.24) | 0.97 (0.81–1.15) | 1.15 (0.96–1.37) | 1.24 (1.06–1.45) | 0.11 | |
| Current light smokers (n = 3,548) | Model 1a | Reference | 1.01 (0.68–1.47) | 0.75 (0.43–1.30) | 0.99 (0.64–1.53) | 0.71 (0.42–1.19) | 1.31 (0.84–2.04) | 1.09 (0.72–1.63) | 0.34 |
| Model 2b | Reference | 0.97 (0.65–1.43) | 0.63 (0.36–1.11) | 0.92 (0.59–1.44) | 0.71 (0.42–−1.21) | 1.24 (0.79–1.94) | 1.09 (0.72–1.66) | 0.23 | |
| Model 3c | Reference | 1.16 (0.71–1.90) | 0.71 (0.37–1.35) | 1.09 (0.63–1.88) | 0.80 (0.43–1.49) | 1.46 (0.85–2.48) | 1.25 (0.78–2.07) | 0.14 | |
| Current heavy smokers (n = 3,458) | Model 1a | Reference | 1.01 (0.71–1.41) | 0.91 (0.60–1.39) | 1.08 (0.74–1.60) | 0.92 (0.63–1.35) | 0.97 (0.65–1.44) | 1.06 (0.74–1.51) | 0.66 |
| Model 2b | Reference | 1.01 (0.71–1.42) | 0.83 (0.54–1.28) | 0.99 (0.67–1.47) | 0.91 (0.62–1.35) | 0.97 (0.65–1.46) | 1.15 (0.80–1.66) | 0.57 | |
| Model 3c | Reference | 0.92 (0.59–1.41) | 0.75 (0.45–1.24) | 0.78 (0.48–1.29) | 0.82 (0.51–1.32) | 0.89 (0.55–1.45) | 1.03 (0.66–1.61) | 0.34 | |
| Former light smokers (n = 3,314) | Model 1a | Reference | 1.24 (0.91–1.70) | 1.03 (0.71–1.51) | 1.20 (0.82–1.76) | 1.36 (0.95–1.97) | 1.37 (0.90–2.08) | 1.29 (0.91–1.83) | 0.07 |
| Model 2b | Reference | 1.28 (0.93–1.75) | 1.01 (0.68–1.48) | 1.19 (0.81–1.75) | 1.44 (0.99–2.09) | 1.36 (0.89–2.08) | 1.41 (0.99–2.02) | 0.06 | |
| Model 3c | Reference | 1.30 (0.90–1.88) | 1.05 (0.68–1.62) | 1.14 (0.74–1.77) | 1.50 (0.99–2.27) | 1.39 (0.87–2.21) | 1.38 (0.93–2.07) | 0.09 | |
| Former heavy smokers (n = 3,202) | Model 1a | Reference | 1.02 (0.76–1.37) | 0.83 (0.58–1.17) | 0.96 (0.67–1.37) | 0.90 (0.64–1.26) | 1.03 (0.71–1.49) | 1.28 (0.93–1.76) | 0.19 |
| Model 2b | Reference | 1.01 (0.75–1.35) | 0.80 (0.57–1.13) | 0.93 (0.65–1.33) | 0.89 (0.63–1.24) | 1.03 (0.71–1.49) | 1.28 (0.93–1.76) | 0.18 | |
| Model 3c | Reference | 0.92 (0.66–1.27) | 0.72 (0.49–1.05) | 0.79 (0.53–1.18) | 0.78 (0.54–1.13) | 0.96 (0.64–1.44) | 1.20 (0.85–1.70) | 0.07 | |
| Never smokers (n = 7,289) | Model 1a | Reference | 1.36 (1.12–1.67) | 1.31 (1.01–1.70) | 1.53 (1.20–1.96) | 1.04 (0.78–1.39) | 1.31 (0.99–1.74) | 1.52 (1.19–1.94) | 0.23 |
| Model 2b | Reference | 1.30 (1.06–1.59) | 1.18 (0.90–1.55) | 1.36 (1.05–1.76) | 0.96 (0.71–1.30) | 1.22 (0.91–1.64) | 1.52 (1.18–1.97) | 0.23 | |
| Model 3c | Reference | 1.31 (1.03–1.66) | 1.28 (0.95–1.73) | 1.42 (1.06–1.89) | 0.97 (0.70–1.34) | 1.24 (0.91–1.70) | 1.51 (1.15–1.99) | 0.24 | |
Referent group was never coffee consumers
OR odds ratio, CI confidence interval
a
Model 1: Crude model
b
Model 2: Adjusted for age, gender and smoking (in the overall analyses)
c
Model 3: Additionally adjusted for water, liquid milk, alcohol, carbonated drinks, tea and juice
p trend < 0.05 were considered statistically significant