Table 1.
Frequency distributions of various risk factors and crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) for new occurrence of urinary tract cancer from multivariable logistic regression models*
| Model 1 |
Model 2 |
|||||||
| Risk factor | Case subjects, N = 4594 | Control subjects, N = 174 701 | Crude OR (95% CI) | P | Adjusted OR (95% CI)‡ | P | Adjusted OR (95% CI)‡ | P |
| Sex | ||||||||
| Female | 1566 | 83 671 | 1.0 (Referent) | 1.0 (Referent) | 1.0 (Referent) | |||
| Male | 3028 | 91 030 | 1.8 (1.7 to 1.9) | <.001 | 1.7 (1.6 to 1.8) | <.001 | 1.7 (1.6 to 1.8) | <.001 |
| Age, y | ||||||||
| <40 | 199 | 115 789 | 1.0 (Referent) | 1.0 (Referent) | 1.0 (Referent) | |||
| 40–59 | 1194 | 42 260 | 16.4 (14.1 to 18.9) | <.001 | 16.2 (14.0 to 18.9) | <.001 | 16.1 (13.9 to 18.8) | <.001 |
| 60–74 | 1932 | 11 308 | 99.3 (85.8 to 115) | <.001 | 96.3 (83.1 to 112) | <.001 | 95.5 (82.4 to 111) | <.001 |
| 75–99 | 1269 | 5344 | 138 (119 to 161) | <.001 | 135 (116 to 158) | <.001 | 135 (116 to 157) | <.001 |
| Residence in township where black foot disease was endemic | ||||||||
| No | 4506 | 174 151 | 1.0 (Referent) | 1.0 (Referent) | 1.0 (Referent) | |||
| Yes | 88 | 550 | 6.2 (4.9 to 7.8) | <.001 | 4.4 (3.4 to 5.8) | <.001 | 4.4 (3.4 to 5.8) | <.001 |
| Chronic UTI | ||||||||
| No | 4511 | 174 091 | 1.0 (Referent) | 1.0 (Referent) | 1.0 (Referent) | |||
| Yes | 83 | 610 | 5.3 (4.2 to 6.6) | <.001 | 1.6 (1.3 to 2.1) | <.001 | 1.6 (1.3 to 2.1) | <.001 |
| Mu-Tong, total amount prescribed, g | ||||||||
| 0 | 3987 | 149 464 | 1.0 (Referent) | 1.0 (Referent) | NA | |||
| 1–60 | 489 | 22 354 | 0.8 (0.7 to 0.9) | <.001 | 1.0 (0.9 to 1.2) | .579 | ||
| 61–100 | 50 | 14859 | 1.3 (0.95 to 1.7) | .108 | 1.6 (1.3 to 2.1) | .003 | ||
| 101–200 | 46 | 10035 | 1.7 (1.3 to 2.3) | <.001 | 2.0 (1.4 to 2.7) | <.001 | ||
| > 200 | 22 | 3953 | 2.1 (1.4 to 3.2) | <.001 | 2.1 (1.3 to 3.4) | .004 | ||
| Each 30-g increase† | NA | NA | 1.1 (1.01 to 1.1) | .016 | 1.1 (1.06 to 1.15) | <.001 | ||
| Fangchi, total amount prescribed, g | ||||||||
| 0 | 3927 | 150 456 | 1.0 (Referent) | 1.0 (Referent) | NA | |||
| 1–60 | 623 | 23 456 | 1.0 (0.9 to 1.1) | .689 | 0.9 (0.8 to 1.0) | .121 | ||
| 61–100 | 15 | 427 | 1.3 (0.8 to 2.2) | .293 | 0.7 (0.4 to 1.2) | .180 | ||
| > 100 | 29 | 362 | 3.1 (2.1 to 4.5) | <.001 | 1.3 (0.9 to 2.0) | .181 | ||
| Xi-Xin, total amount prescribed, g | ||||||||
| 0 | 3680 | 139 385 | 1.0 (Referent) | 1.0 (Referent) | NA | |||
| 1–100 | 839 | 33 072 | 1.0 (0.9 to 1.04) | .303 | 1.1 (1.003 to 1.2) | .044 | ||
| 101–300 | 54 | 1917 | 1.1 (0.8 to 1.4) | .641 | 0.7 (0.4 to 1.2) | .246 | ||
| > 300 | 21 | 327 | 2.4 (1.6 to 3.8) | <.001 | 1.3 (0.9 to 2.0) | .412 | ||
| Aristolochic acid, estimated total consumption, mg | ||||||||
| 0 | 3274 | 121 820 | 1.0 (Referent) | NA | 1.0 (Referent) | |||
| 1–150 | 1151 | 48 869 | 0.9 (0.8 to 0.9) | <.001 | 1.0 (0.96 to 1.1) | .348 | ||
| 151–250 | 69 | 2032 | 1.3 (0.99 to 1.6) | .59 | 1.4 (1.1 to 1.8) | .012 | ||
| 251–500 | 64 | 1403 | 1.7 (1.3 to 2.2) | <.001 | 1.6 (1.2 to 2.1) | <.001 | ||
| > 500 | 36 | 577 | 2.3 (1.7 to 3.3) | <.001 | 2.0 (1.4 to 2.9) | <.001 | ||
| Each 100-mg increase† | NA | NA | 1.1 (1.03 to 1.1) | <.001 | 1.1 (1.06 to 1.13) | <.001 | ||
*
NA = not applicable; UTI = urinary tract infection.
†
Estimation of OR based on continuous variable for every 30-g increment of Mu Tong or 100-mg increment of aristolochic acid.
‡
Logistic regression models for different dosages of Chinese herbs (model 1) and different estimated dosages of aristolochic acid as risk factors (model 2) were adjusted for age, sex, residence in a township where black foot disease was endemic, and history of chronic UTI.