Table 1.

Selected characteristics of cases and controls in the New England Bladder Cancer Study with total THM assignments for $\ge \mathrm{70}\%$ of lifetime residential history, $\mathrm{2001–2004}$.

Condition	Cases ($n=\mathrm{1,061}$)	Controls ($n=\mathrm{1,290}$)
Age, y
$<55$	175 (16.5)	228 (17.7)
55–64	271 (25.5)	299 (23.2)
65–74	390 (36.8)	498 (38.6)
$\ge 75$	225 (21.2)	265 (20.5)
Sex
Male	805 (75.9)	945 (73.3)
Female	256 (24.1)	345 (26.7)
State
Maine	521 (49.1)	667 (51.7)
New Hampshire	353 (33.3)	395 (30.6)
Vermont	187 (17.7)	228 (17.7)
Race
White	996 (93.9)	1,218 (94.4)
Mixed race	54 (5.1)	56 (4.4)
Other	11 (1.0)	16 (1.2)
Hispanic ethnicity
No	22 (2.1)	22 (1.0)
Yes	1,039 (97.9)	1,266 (98.1)
Don’t know	0	2 (0.9)
Smoking statusa
Nonsmoker	19 (1.8)	36 (2.8)
Occasional smoker	157 (14.8)	438 (34.0)
Former smoker	543 (51.2)	626 (48.6)
Current Smoker	341 (32.2)	189 (14.7)
Employment in a high-risk occupationb
Never worked in paying job	11	9
Never worked in high-risk occupation	465 (44.3)	871 (68.0)
Ever worked in high-risk occupation	585 (55.7)	410 (32.0)

Note: Controls were frequency-matched on age, sex, and state of residence. THM, trihalomethane.

^aOccasional smokers were defined as subjects who had smoked $>100$ cigarettes overall but never smoked cigarettes regularly. Former smokers were regular smokers who had quit smoking $\ge 1$ y before diagnosis (cases) or selection date (controls). Current smokers were regular smokers who were still smoking or who had quit within 1 y of diagnosis or selection.

^bHigh-risk occupations included metal workers, textile machine operators, mechanics/repairers, automobile mechanics, plumbers, computer systems analysts, landscape industry workers, health services, cleaning and building services, electronic components manufacturing, and transportation equipment manufacturing.