Table 1. Risk categories and examples for the classification of patients with special risks.

	Surgical	Non-surgical*
Low VTE risk	Minor surgical interventions Trauma without or with minor soft tissue injury No additional or only minor dispositional risk, otherwise classification in higher risk category	Infection or acute inflammatory disease without bed confinement Central venous catheter/port catheter No additional or only minor dispositional risk, otherwise classification in higher risk category
Moderate VTE risk	Longer surgical interventions Joint-spanning cast immobilization of the lower extremity Arthroscopy assisted surgery on the lower extremity No additional or only minor dispositional risk, otherwise classification in higher risk category	Acute heart failure (NYHA III/IV) Acute decompensation in patients with severe COPD without ventilation Infection or acute inflammatory disease with bed confinement status Malignant disease requiring in-patient treatment No additional or only minor dispositional risk, otherwise classification in higher risk category
High VTE risk	Major surgery in the abdominal and pelvic region for malignancy or inflammatory disease Patients with multiple injuries, serious injuries of the spine, the pelvis and/or the lower extremity Major surgery on the spine, pelvis, hip and knee Major surgery in the body cavities of the chest, abdomen and/or pelvic region	Stroke with leg paresis Acute decompensation in patients with severe COPD with ventilation Sepsis Seriously ill patients receiving intensive care

^*Study data are only available for in-patient care. VTE, venous thromboembolism; NYHA, New York Heart Association; COPD, chronic obstructive pulmonary disease