Many risk factors for venous thromboembolism (VTE) in hospitalized medical patients are also present in medical outpatients. VTE prevention represents an important challenge for physicians treating patients at home. The AT-HOME study was a prospective cross-sectional observational study designed to assess awareness of the risk of VTE in immobilized acutely ill medical outpatients among German physicians, many of whom were participating in a national Continuing Medical Education (CME) program designed to raise awareness of VTE. The study involved 1210 medical patients who were acutely confined to bed at home. Physicians performed a subjective assessment of VTE risk, which was rated on a 10-point scale (1 = very low risk; 10 = very high risk). The risk of VTE was also assessed retrospectively by using a scorecard developed for use in hospitalized medical patients. Of the 1210 patients, 198 (16%) had risk scores of 0-4, 319 (26%) had scores of 5 or 6, and 693 (57%) had scores > or =7. Overall, 966 patients (80%) received thromboprophylaxis. The proportion of patients receiving thromboprophylaxis was 0% to 47% in risk score groups 0-4, 76% to 85% in groups 5 and 6, and 90% to 100% in risk score groups 7-10. In the retrospective assessment of VTE risk, 74% of patients were at high risk, 15% were at intermediate risk, and 11% were at low risk. The proportions of patients receiving thromboprophylaxis in these groups were 87%, 61%, and 55%, respectively. The involvement of physicians in educational activities focusing on VTE awareness appeared to create awareness of the risks of VTE in acutely ill medical outpatients.