TABLE 3.
Hazard ratios (HR) (95% confidence intervals [CI]) of study factors for squamous cell carcinoma
| Cases | Person years | Age, PHC‐adjusted HR (95% CI) | P trend a | Multivariable‐adjusted HR (95% CI) b | P trend a | |
|---|---|---|---|---|---|---|
| Men | ||||||
| Occupation type | ||||||
| Indoor workers | 22 | 615 269 | 1.00 | 1.00 | ||
| Outdoor workers | 29 | 219 052 | 2.00 (1.09‐3.68) | .026 | 2.18 (1.17‐4.04) | .014 |
| Alcohol consumption | ||||||
| Non/occasional drinkers | 18 | 263 745 | 1.00 | 1.00 | ||
| Regular drinkers | 33 | 570 577 | 0.96 (0.53‐1.74) | .900 | 0.96 (0.53‐1.74) | .898 |
| Coffee consumption | ||||||
| No | 23 | 247 600 | 1.00 | 1.00 | ||
| Yes | 28 | 586 721 | 0.70 (0.40‐1.22) | .205 | 0.74 (0.42‐1.31) | .302 |
| Smoking status | ||||||
| Never smokers | 14 | 203 259 | 1.00 | 1.00 | ||
| Former smokers | 21 | 199 934 | 1.34 (0.68‐2.66) | 1.38 (0.69‐2.75) | ||
| Current smokers | 16 | 431 129 | 0.64 (0.31‐1.32) | .163 | 0.69 (0.33‐1.44) | .261 |
| Physical activity | ||||||
| No | 34 | 540 179 | 1.00 | 1.00 | ||
| Yes | 17 | 294 142 | 1.12 (0.62‐2.03) | .700 | 1.21 (0.67‐2.21) | .529 |
| BMI (kg/m2) | ||||||
| <23 | 23 | 367 167 | 0.98 (0.50‐1.91) | 1.02 (0.52‐2.00) | ||
| 23‐25 | 14 | 234 851 | 1.00 | 1.00 | ||
| ≥25 | 14 | 232 303 | 1.12 (0.53‐2.35) | .717 | 1.05 (0.50‐2.21) | .945 |
| Family history of cancer | ||||||
| No | 34 | 6 564 805 | 1.00 | 1.00 | ||
| Yes | 17 | 179 516 | 1.90 (1.05‐3.45) | .034 | 1.99 (1.10‐3.62) | .024 |
| Women | ||||||
| Occupation | ||||||
| Indoor workers | 26 | 755 112 | 1.00 | 1.00 | ||
| Outdoor workers | 21 | 240 380 | 1.37 (0.75‐2.52) | .310 | 1.26 (0.68‐2.32) | .465 |
| Coffee consumption | ||||||
| No | 25 | 314 830 | 1.00 | 1.00 | ||
| Yes | 22 | 680 662 | 0.69 (0.38‐1.24) | .213 | 0.72 (0.39‐1.31) | .284 |
| Physical activity | ||||||
| No | 37 | 748 108 | 1.00 | 1.00 | ||
| Yes | 10 | 247 384 | 0.72 (0.36‐1.47) | .371 | 0.76 (0.37‐1.55) | .452 |
| BMI (kg/m2) | ||||||
| <23 | 20 | 476 847 | 1.00 (0.49‐2.05) | 0.96 (0.47‐1.96) | ||
| 23‐25 | 12 | 241 361 | 1.00 | 1.00 | ||
| ≥25 | 15 | 277 283 | 0.92 (0.43‐1.97) | .814 | 0.95 (0.45‐2.04) | .919 |
PHC, public health center.
The men who are outdoor workers or have a family history of cancer had an increased risk of SCC (In bold).
a
P for trend was calculated by entering the ordinal values of each group as a continuous term into the models.
b
Adjusted for age, area, occupational type, alcohol consumption, coffee consumption, smoking status, physical activity, body mass index (BMI), family history of cancer mutually, and green tea, Chinese tea, black tea consumption.