Table 2. Data from participants enrolled in the secondary case-control study.
| Variable | Cases | Controls | P | ||
| No. | % | No. | % | ||
| Age (years) | 51.45±14.36 | 50.26±14.52 | 0.063 | ||
| Sex | 0.970 | ||||
| Male | 532 | 53.04% | 546 | 52.96% | |
| Female | 471 | 46.96% | 485 | 47.04% | |
| Smoking | 0.009 | ||||
| Yes | 227 | 22.6% | 185 | 17.9% | |
| No | 776 | 77.4% | 846 | 82.1% | |
| Alcohol drinker | 0.717 | ||||
| Yes | 117 | 11.7% | 115 | 11.2% | |
| No | 886 | 88.3% | 916 | 88.8% | |
| Malignant tumor | 1.207×10−13 | ||||
| Yes | 65 | 6.5% | 5 | 0.5% | |
| No | 938 | 93.5% | 1026 | 99.5% | |
| T2DM | 0.037 | ||||
| Yes | 42 | 4.2% | 26 | 2.5% | |
| No | 961 | 95.8% | 1005 | 97.5% | |
| Sedentariness | 0.031 | ||||
| Yes | 23 | 2.3% | 11 | 1.1% | |
| No | 980 | 97.7% | 1020 | 98.9% | |
| Pregnancy/puerperium | |||||
| Yes | 26 | 2.6% | 14 | 1.4% | 0.045 |
| No | 977 | 97.4% | 1017 | 98.6% | |
Years of age were expressed as mean±standard deviation. Age of cases: age at the first incident. Age of controls: age at enrollment. Age was further divided into three levels: under 40 years, 40 to 60 years, and over 60 years. Sedentariness/immobilization reflects the 4 weeks prior to the venous thrombosis incident. A Chi-squared test was used to compare the differences between groups according to gender, smoking status, alcohol abuse, malignant tumor, type 2 diabetes, sedentariness/immobilization, and pregnancy/puerperium. A Student's t test was used to compare the mean ages of the cases and controls. VT = venous thrombosis. T2DM = type 2 diabetes mellitus.