Table 4

Incidence rate ratios for bladder cancer for occupational exposures (ever exposed v non-exposed (exp v non)) stratified upon cigarette smoking habit and cigarette smoking amount; Netherlands cohort study (1986–92)

Cigarette smoking		Paint components				PAH^4-150			Diesel exhaust
Cigarette smoking		Cases (exp v non)^4-150	RR (95% CI)^4-151			Cases (exp v non)^4-150	RR (95% CI)^4-151		Cases (exp v non)^4-150	RR (95% CI)^4-151
Never smoker^4-153	2/34	1.35 (0.26 to 7.12)		0/36	Too few cases		2/34	0.51 (0.11 to 2.35)
Smoking status
Former^4-160	13/223^4-152	0.65 (0.34 to 1.26)		15/221^4-152	0.67 (0.36 to 1.27)		46/190^4-152	1.01 (0.68 to 1.49)
<15^4-151 cigarettes/day^4-164	5/64	1.13 (0.37 to 3.43)		4/64	0.59 (0.19 to 1.79)		7/61	0.38 (0.11 to 1.28)
⩾15^4-151 cigarettes/day^4-164	8/151	0.42 (0.17 to 1.03)		11/149	0.25 (0.00 to 4.28)		38/122	1.37 (0.74 to 2.56)
Current^4-160	32/223^4-152	2.22 (1.15 to 4.29)		24/228^4-152	1.16 (0.60 to 2.23)		50/201^4-152	1.24 (0.81 to 1.90)
<15^4-151 cigarettes/day^4-164	9/65	1.40 (0.50 to 3.93)		7/67	1.37 (0.25 to 7.44)		15/57	0.99 (0.41 to 2.43)
⩾15^4-151 cigarettes/day^4-164	20/129	3.53 (1.52 to 8.22)		16/131	1.61 (0.62 to 4.17)		29/119	1.22 (0.63 to 2.39)

↵4-150 Number of exposed and non-exposed bladder cancer cases included in the analysis.
↵4-151 Adjusted for age and other occupational exposures.
↵4-152 The numbers of exposed and non-exposed cases in the strata of cigarette smoking amount might not add up due to missing data on the number of cigarettes smoked per day.
↵4-153 The reference category (RR=1.0) is formed by subjects not exposed to the corresponding occupational risk factor.
↵4-160 Adjusted for age, other occupational exposures, cigarette smoking amount (cigarettes/day), and cigarette smoking duration (y).
↵4-164 Adjusted for age, other occupational exposures, and cigarette smoking duration (y).
PAHs=polycyclic aromatic hydrocarbons.