Table 2.
Incidence rates and hazard ratios (95% CIs) for cigarette smoking and bladder cancer by sex
Men | Women | |||||||
---|---|---|---|---|---|---|---|---|
Category | Person- years |
N | Age-standardized incidence rates/105 person-years (95% CI) |
Multivariate adjusted HR* (95% CI) |
Person- years |
N | Age-standardized incidence rates/105 person-years (95% CI) |
Multivariate adjusted HR* (95% CI) |
Never smoked cigarettes, pipes, or cigars | 677,607 | 461 | 69.8 (63.4–76.1) | 1.00 (ref) | 821,064 | 133 | 16.1 (13.4–18.8) | 1.00 (ref) |
Never smoked cigarettes but smoked pipes or cigars | 148,810 | 143 | 92.5 (77.3–107.7) | 1.29 (1.07–1.56) | 635 | 0 | --- | --- |
Former smoker (overall)† | 1,540,789 | 2,483 | 154.6 (148.5–160.7) | 2.14 (1.92–2.37) | 70,595 | 288 | 40.7 (36.0–45.5) | 2.52 (2.05–3.10) |
Stopped ≥ 10 years ago | 1,237,120 | 1850 | 140.2 (133.8–146.7) | 1.93 (1.73–2.14) | 499,493 | 171 | 33.6 (28.6–38.6) | 2.08 (1.65–2.61) |
Stopped 5–<10 years ago | 197,325 | 394 | 206.9 (186.4–227.4) | 2.85 (2.49–3.27) | 127,140 | 69 | 55.7 (42.5–68.9) | 3.49 (2.61–4.67) |
Stopped 1–5 years ago | 106,344 | 239 | 243.3 (212.2–274.4) | 3.32 (2.84–3.89) | 79,292 | 48 | 65.2 (46.7–83.7) | 3.97 (2.85–5.53) |
1–10 cigarettes/day | 314,144 | 309 | 96.6 (85.8–107.3) | 1.33 (1.15–1.55) | 273,297 | 80 | 29.4 (22.9–35.8) | 1.80 (1.36–2.38) |
11–20 cigarettes/day | 476,611 | 709 | 142.3 (131.8–152.8) | 1.90 (1.68–2.15) | 214,073 | 88 | 41.2 (32.6–49.8) | 2.50 (1.91–3.27) |
21–30 cigarettes/day | 324,709 | 596 | 180.4 (165.9–194.9) | 2.40 (2.11–2.72) | 110,881 | 66 | 61.1 (46.3–75.9) | 3.75 (2.78–5.04) |
31–40 cigarettes/day | 222,928 | 448 | 197.4 (179.1–215.7) | 2.62 (2.29–2.99) | 63,451 | 29 | 46.8 (29.7–63.9) | 2.86 (1.91–4.28) |
> 40 cigarettes/day | 202,397 | 421 | 205.7 (186.1–225.4) | 2.71 (2.36–3.10) | 44,223 | 25 | 60.4 (36.6–84.3) | 3.65 (2.38–5.60) |
Current smoker (overall)† | 323,114 | 809 | 276.4 (256.9–295.8) | 3.89 (3.46–4.37) | 300,996 | 206 | 73.6 (63.4–83.8) | 4.65 (3.73–5.79) |
1–10 cigarettes/day | 66,437 | 131 | 204.5 (169.4–239.6) | 3.11 (2.54–3.80) | 94,120 | 53 | 58.3 (42.5–74.0) | 3.81 (2.76–5.25) |
11–20 cigarettes/day | 120,202 | 319 | 281.9 (250.7–313.1) | 4.14 (3.56–4.81) | 127,433 | 88 | 72.2 (57.0–87.4) | 4.78 (3.64–6.27) |
21–30 cigarettes/day | 75,950 | 204 | 295.4 (253.9–336.8) | 4.34 (3.66–5.16) | 53,174 | 44 | 88.6 (62.0–115.2) | 5.93 (4.20–8.37) |
31–40 cigarettes/day | 43,407 | 113 | 283.1 (228.6–337.6) | 4.33 (3.50–5.35) | 20,666 | 17 | 98.3 (49.3–147.3) | 6.02 (3.62–9.99) |
> 40 cigarettes/day | 17,118 | 42 | 271.5 (185.3–357.7) | 4.14 (3.00–5.70) | 5,605 | 4 | 66.4 (0–132.9) | 5.19 (1.92–14.05) |
Adjusted for age, education, ethnicity, and pipe and cigar use.
Linear trend tests across categories of cigarette smoking were conducted by assigning participants their appropriate category of cigarette smoking and entering this variable as a continuous term in the regression model. P-values were then obtained from the Wald test. All p-values for the test of trend were less than 0.0001.