Table 2.
Hazard ratios of colorectal cancer by THM exposure categories in the 58 672 men and women in SIMPLER stratified by sexa
| THM | Non-chlorinated | Low THM (<15 µg/L) | High THM (≥15 µg/L) |
|---|---|---|---|
| Men, n = 32 872 | |||
| No. of participants | 5785 | 18 050 | 9037 |
| Cases | 176 | 650 | 341 |
| Person-years | 94 558 | 294 357 | 147 707 |
| Age-adjusted HR (95% CI)b | 1.00 | 1.20 (1.02 to 1.42) | 1.26 (1.05 to 1.51) |
| Multivariable adjusted HR (95% CI)e | 1.00 | 1.23 (1.03 to 1.47) | 1.26 (1.05 to 1.51) |
| Women, n = 25 800 | |||
| No. of participants | 4534 | 11 376 | 9890 |
| Cases | 136 | 322 | 288 |
| Person-years | 77 702 | 199 926 | 173 960 |
| Age-adjusted HR (95% CI)b | 1.00 | 0.93 (0.76 to 1.14) | 0.97 (0.79 to 1.19) |
| Multivariable adjusted HR (95% CI)c | 1.00 | 0.93 (0.74 to 1.17) | 0.97 (0.77 to 1.23) |
The sum of chloroform, bromoform, dibromochloromethane, and bromodichloromethane. CI = confidence interval; HR = hazard ratio; THM = trihalomethanes.
Adjusted for age (underlying timescale) and cohort (stratum variable).
Further adjusted for level of education (<9, 9, 10-11, 12, and >12 years), household income (1000 SEK, quartiles), smoking status (never, former <10, former ≥10, current <10, or current ≥10 cigarettes/day), body mass index (<20, 20-24.9, 25-29.9, or ≥30 kg/m2), diabetes (yes/no), physical activity (walking >40 minutes/day or exercise >60 minutes/week, yes/no), alcohol intake (<5, 5-14.9, or ≥15 g/day), intake of red meat (servings/week, quartiles), intake of processed meat (servings/week, quartiles), intake of dairy products (servings/day, quartiles), intake of whole-grain foods (servings/week, quartiles), total energy intake (kcal/day, continuous), use of calcium supplements (yes/no), and drinking-water calcium (mg/L, continuous).