Table 2 Dose-response relationship between smoking and CRC deaths among subgroups
Men | Women | |||||||
|---|---|---|---|---|---|---|---|---|
Control (%) | Case (%) | Crude OR (95% CI) | Age-adjusted OR (95% CI) | Control (%) | Case (%) | Crude OR (95% CI) | Age-adjusted OR (95% CI) | |
Urban | ||||||||
Non-smoker | 4510 (43.90) | 2180 (42.44) | 1.000 | 1.000 | 8322 (83.40) | 4108 (82.34) | 1.000 | 1.000 |
Years of smoking | ||||||||
<20 | 602 (5.86) | 267 (5.20) | 0.917 (0.788–1.069) | 0.851 (0.715–1.014) | 171 (1.71) | 79 (1.58) | 0.936 (0.715–1.225) | 0.944 (0.721–1.236) |
20∼29 | 750 (7.30) | 355 (6.91) | 0.979 (0.855–1.122) | 0.973 (0.905–1.045) | 221 (2.21) | 102 (2.04) | 0.935 (0.737–1.186) | 0.970 (0.861–1.093) |
⩾30 | 4412 (42.44) | 2335 (45.45) | 1.095 (1.019–1.176) | 1.030 (1.006–1.055) | 1264 (12.67) | 700 (14.03) | 1.122 (1.016–1.239) | 1.033 (0.998–1.068) |
P for trend | <0.001 | 0.045 | ||||||
Cigarettes smoked daily | ||||||||
<10 | 1605 (15.62) | 804 (15.65) | 1.036 (0.939–1.144) | 1.037 (0.939–1.145) | 802 (8.04) | 392 (7.86) | 0.990 (0.873–1.124) | 0.982 (0.865–1.115) |
10∼19 | 2027 (19.73) | 941 (18.32) | 0.960 (0.875–1.054) | 0.979 (0.935–1.026) | 555 (5.56) | 290 (5.81) | 1.069 (0.914–1.226) | 1.023 (0.951–1.102) |
⩾20 | 2132 (20.75) | 1212 (23.59) | 1.176 (1.078–1.283) | 1.056 (1.026–1.088) | 299 (3.00) | 199 (3.99) | 1.348 (1.123–1.619) | 1.102 (1.037–1.171) |
P for trend | <0.001 | 0.008 | ||||||
Age at onset of smoking | ||||||||
>20 | 2883 (28.06) | 1440 (28.03) | 1.033 (0.953–1.121) | 1.034 (0.953–1.122) | 1017 (10.19) | 524 (10.50) | 1.044 (0.933–1.167) | 1.034 (0.924–1.157) |
⩽20 | 2881 (28.04) | 1517 (29.53) | 1.089 (1.005–1.181) | 1.043 (1.002–1.086) | 639 (6.40) | 357 (7.16) | 1.132 (0.989–1.295) | 1.058 (0.989–1.133) |
P for trend | <0.001 | 0.062 | ||||||
Rural | ||||||||
Non-smoker | 1132 (37.14) | 480 (31.50) | 1.000 | 1.000 | 2364 (91.49) | 1168 (90.40) | 1.000 | 1.000 |
Years of smoking | ||||||||
<20 | 200 (6.56) | 83 (5.45) | 0.979 (0.742–1.291) | 0.829 (0.597–1.150) | 28 (1.08) | 15 (1.16) | 1.084 (0.577–2.038) | 1.106 (0.588–2.081) |
20∼29 | 293 (9.61) | 142 (9.32) | 1.143 (0.911–1.434) | 1.024 (0.903–1.160) | 24 (0.93) | 14 (1.08) | 1.181 (0.609–2.291) | 1.089 (0.782–1.517) |
⩾30 | 1423 (46.69) | 819 (53.74) | 1.357 (1.184–1.557) | 1.109 (1.059–1.162) | 168 (6.50) | 95 (7.35) | 1.145 (0.881–1.486) | 1.040 (0.952–1.135) |
P for trend | <0.001 | 0.268 | ||||||
Cigarettes smoked daily | ||||||||
<10 | 628 (20.60) | 315 (20.67) | 1.183 (0.996–1.405) | 1.183 (0.995–1.405) | 134 (5.19) | 67 (5.19) | 1.012 (0.749–1.368) | 1.000 (0.739–1.358) |
10∼19 | 657 (21.56) | 321 (21.06) | 1.152 (0.971–1.367) | 1.071 (0.983–1.167) | 63 (2.44) | 42 (3.25) | 1.162 (0.953–1.416) | 1.155 (0.947–1.409) |
⩾20 | 631 (20.70) | 408 (26.77) | 1.525 (1.294–1.797) | 1.148 (1.086–1.213) | 23 (0.89) | 15 (1.16) | 1.097 (0.882–1.364) | 1.095 (0.880–1.362) |
P for trend | <0.001 | 0.136 | ||||||
Age at onset of smoking | ||||||||
>20 | 1026 (33.66) | 517 (33.92) | 1.188 (1.023–1.381) | 1.195 (1.028–1.389) | 163 (6.31) | 87 (6.73) | 1.080 (0.825–1.414) | 1.064 (0.812–1.394) |
⩽20 | 890 (29.20) | 527 (34.58) | 1.397 (1.200–1.625) | 1.177 (1.090–1.270) | 57 (2.21) | 37 (2.86) | 1.314 (0.864–1.999) | 1.145 (0.928–1.412) |
P for trend | <0.001 | 0.185 | ||||||
