Occupational effect on the occurrence of idiopathic venous thromboembolism

Few studies have explored the effects of various occupations on venous thromboembolism occurrence. We examined idiopathic venous thromboembolism (IVTE) occurrence by occupation, body size, and age in the U.S. military. To capture idiopathic cases, exclusion criteria included recognized venous thromboembolism risk factors. Each case was matched to three controls on branch of service, sex, rank/grade, race, and education level. Body mass index, age, and occupation were analyzed with χ² and logistic regression. Of 2,167 cases, most were male (87%), white (69%), enlisted (78%), averaging 36 years old. IVTE odds increased with age (p < 0.001). Every occupation showed greater odds than pilots/aircrew (p < 0.001), especially infantry/artillery/combat arms, which showed twice the odds, followed by health care workers. Normal weight was protective, especially in pilots/aircrew (OR 0.52, p = 0.03) and repair/engineering (OR 0.72, p < 0.001). Our analysis found a lower risk of IVTE among pilots and aircrew compared to other military occupations. Body size had less impact than expected in aircraft and vehicle operators. Greater odds in health care workers and infantry/artillery/combat arms than in pilots/aircrew and armor/motor transport occupational groups may reflect prolonged standing. Limitations include potential miscoding of health records and potential misclassification. Future IVTE research should explore job functions and worker characteristics.