Home treatment of deep vein thrombosis. An out-patient treatment model with once-daily injection of low-molecular-weight heparin (tinzaparin) in 555 patients

Abstract

During a 22-month period, 555 consecutive patients at seven hospitals in the western part of Sweden with an acute deep vein thrombosis (DVT) not involving the iliac vein and not having pulmonary embolism were included in a study testing the efficacy of implementing out-patient treatment. For all patients with a confirmed diagnosis of acute DVT, a folder was used that contained two checklists with detailed instructions for further treatment, one for the doctor and one for the nurse, an information pamphlet for the patient and prepared prescriptions for low-molecular-weight heparin (LMWH) tinzaparin (Innohep) of 175 anti-Xa IU/kg body weight subcutaneously once daily and warfarin. Patients not requiring hospitalisation, according to strict guidelines, were then eligible for treatment as out-patients. Prior to release from the emergency department for home treatment, a nurse provided detailed information to the patient and administered the first tinzaparin injection. In 194 (35.0%) out of 555 patients, the DVT was localised only in the lower leg not reaching the popliteal vein. Factors predisposing to venous thromboembolism were identified in 35.0% of the patients. 332 (59.8%) out of the 555 patients studied did not require hospitalisation and were therefore treated as out-patients. 140 of these patients (42.2%) injected themselves, the injection was given by a relative in 63 (19.0%) patients and by the community nurse in 129 (38.9%). Six (1.8%) patients reported a worsening of the DVT condition during the LMWH treatment period. No major bleedings were observed during the injection treatment period. Except for local minor skin bleedings at the injection site, only 3 (0.9%) patients reported minor bleedings during the injection treatment period. Recurrences of venous thromboembolism during the first 2 months were reported in 9 patients (2.7%) out of 332 patients who were sent home from the emergency department. Five (2.2%) patients out of the 223 who were admitted to the hospital had an increased tendency to bleeding. Twelve patients (5.4%) were hospitalised because of a pronounced local status, 26 (11.7%) were senile, social factors were the reason for hospitalisation in 76 (34.1%) and lack of time of the physician in 39 (17.5%) of the patients. A pharmacoeconomic analysis found a cost reduction of 69% with the present model for home treatment compared with traditional in-hospital treatment of DVT patients. We conclude that tinzaparin can be safely used at home by patients with DVT below the inguinal region and that the model used in the present study is cost-effective.