This is a clinical trial including non-surgical patients, 70 years of age or older, with renal impairment requiring pharmacological venous thromboembolism prevention during hospitalization. Patients are randomized to receive either 20 mg or 30mg of enoxaparin. Both dosing regimens of enoxaparin have been approved for thromboprophylaxis in impaired kidney function in different countries. Therefore, this study aims to evaluate the efficacy and safety of enoxaparin 20mg versus 30mg subcutaneously daily by comparing anti-xa levels, thrombosis and bleeding events.

Inclusion Criteria:

• Non-surgical patients
• 70 years of age or older
• With renal impairment (creatinine clearance ≤35ml/min)
• Requiring pharmacological thromboprophylaxis

Exclusion Criteria:

• Indication for a treatment dose of anticoagulant treatment
• Knee surgery or hip surgery within 10 to 35 days, respectively
• Surgery, trauma, hemodialysis, peritoneal dialysis, or bleeding
• History of heparin-induced thrombocytopenia
• Known or suspected hypersensitivity to any component of study drug
• Patients with an excessive risk of bleeding and not eligible for pharmacological thromboprophylaxis based on physician assessment or due to any of the 3 major risk factors including active gastroduodenal ulcer, bleeding within the past three months prior to hospital admission, or a platelet count of <50,000 platelets/ mm3