Objective: To estimate the risk factors of VTE focusing on oral pill use, alcohol intake and smoking among women who attended at King Chulalongkorn Memorial Hospital between 1 January 1995 and 31 December 2004.
Material and Method: The study design was case-control study. A Case was defined as the female inpatient who was diagnosed with VTE and a control was defined as the healthy female patient who attended gynecological clinic for annual check up. The questionnaires were developed to interview both cases and controls. The ratio of case per control was 1:2. The data was analyzed with SPSS/PC+ version 12.0. The statistic uses were mean, standard deviation, t-test, Odds ratio and 95% confidence interval.
Results: Seventy of cases and one hundred and forty of controls were recruited into the study. The mean +/- SD of age of case was 37.2 +/- 9.3 years and the control was 35.6 +/- 9.9 years. There were no significant difference in term of age, parity, weight, height and BMI between cases and controls. The Odds ratio of oral contraceptive pill use, smoking and alcohol consumption were 0.94, 4.28, and 2.62, respectively. However, no statistical significance difference of Odds ratio in oral contraceptive pill use, and alcohol consumption were demonstrated.
Conclusion: Smoking and alcohol consumption increased risk of VTE in this study. Oral contraceptive pill use did not demonstrate increasing risk. However, there was no statistical significance of odds ratio in alcohol consumption. This result may be due to the small sample of cases. The further study should be recruited with more cases in order to demonstrated the risk factors of these female patients.

Keywords: Risk factors, Venous thromboembolism