Prolonged seated immobility at work is a common risk factor for venous thromboembolism leading to hospital admission.

The role of seated immobility at work in the pathogenesis of venous thromboembolism (VTE) is uncertain. In this case series, 61 patients aged <65 years with a recent admission for deep venous thrombosis and/or pulmonary embolism completed an interviewer-administered questionnaire to obtain information regarding risk factors. Prolonged seated immobility at work in the 4 weeks before the VTE event was defined as being seated at least 8 h in a 24-h period and at least 3 h at a time without getting up, at least 10 h in a 24-h period and at least 2 h at a time without getting up or at least 12 h in a 24-h period and at least 1 h at a time without getting up. The most commonly identified risk factors were family history of VTE (21 of 61, 34%), seated immobility at work (21 of 61, 34%) and a thrombophilic state (19 of 61, 31%). We conclude that prolonged seated immobility at work may represent a common and important risk factor for VTE.