(6-9%Y.) control vs 8/106 (7.5%) treated, a non-significant 12% increase (SD 56, 2p

The annual incidence of recurrent venous thromboembolism is high during the first years following a first episode, but seems to decline thereafter. Therefore, our results challenge current practice of prescribing lifelong warfarin therapy after a first or second episode of venous thromboembolism in patients with antithrombin or protein C or S deficiency.

SummaryTwo clinical trials in patients with acute deep venous thrombosis have indicated that the outpatient management with fixed-dose, subcutaneous low-molecular-weight heparin is at least as effective and safe as inpatient treatment with unfractionated intravenous heparin with respect to recurrent venous thromboembolism and major bleeding. We performed an economic evaluation alongside one of these trials to assess the cost consequences of the outpatient management strategy. Data were collected through case record forms, complemented by a prospective questionnaire in 78 consecutive patients, interviews with health care providers, and hospital data bases. Our study demonstrated that seventy-five percent of patients allocated to low-molecular-weight heparin received treatment either entirely at home or after a brief hospital stay. Fifteen percent of these patients required professional domiciliary care. Within-centre comparisons of resource utilisation in terms of natural units showed that outpatient management with low-molecular-weight heparin reduced the average number of hospital days in the initial treatment period in nine centres by 59 percent (95% CI: 43 to 71 percent) accompanied by a limited increase in outpatient and professional domiciliary care. The average reduction in hospital days at the end of follow up was 40 percent (95% CI: 25 to 54 percent). A cost-minimisation analysis, focusing on resource utilisation directly related to the treatment of deep venous thrombosis and associated costs in one centre demonstrated a cost reduction of 64 percent (95% CI: 56 to 72 percent) with the outpatient management with low-molecular-weight heparin. These data suggest that outpatient management of patients with proximal venous thrombosis using low-molecular-weight heparin reduces resource utilisation and total treatment cost. Implementation should be preceded by a cautious evaluation of a potential cost shifting and organisational prerequisites.

The correct approach to the management of the asymptomatic carrier with a recognized inherited thrombophilic disorder is uncertain because reliable in formation of the risk of spontaneous (unprovoked) throm bosis in these disorders is not available. To determine the best available estimate of the annual incidence of spon taneous thrombosis in asymptomatic carriers of disorders that have been linked to familial thrombophilia, we per formed a literature review. Using Medline search from 1965 to 1992, supplemented by manual searches, we re trieved all articles that presented data on antithrombin III, protein C, protein S, dysfibrinogenemia, plasmino gen, histidine-rich glycoprotein, heparin cofactor II, and fibrinolysis in relation to thrombosis. Publications were included in the analysis if they (1) reported one or more probands with thrombotic disease and a heterozygous biochemical abnormality of the hemostatic system, (2) assessed the presence of this abnormality in family mem bers independent of the presence or absence of a history of thrombotic disease, and (3) assessed the presence of a history of thrombotic disease in all available family mem bers. The biochemical status and clinical details of all family members reported were extracted from each eligi ble article. For each abnormality the odds ratio for throm bosis was compared in family members with and without the biochemical abnormality. If applicable, thrombosis- free survival and age-specific incidences of thrombosis were calculated. The thrombotic episodes were classified as spontaneous or secondary to a recognized risk factor, and the proportion of spontaneous episodes was calcu lated. The influence of diagnostic suspicion bias in symp tomatic patients with a family history of thrombosis was reduced by recalculating the absolute incidence of throm bosis from the odds ratio after adjusting the incidence of venous thrombosis in nonaffected family members to that observed in the general population. Statistically signifi cant associations between the presence of a biochemical abnormality and a history of venous thrombosis were found for antithrombin III deficiency types 1 and 2a and 2b, protein C deficiency type 1, and protein S deficiency type I. Dysfibronogenemia was statistically significantly associated with venous as well as arterial thrombosis. Thirty-five to 67% of the events were classified as being provoked, as they occurred following exposure to a rec ognized risk factor for thrombosis. The recalculated an nual incidence of spontaneous thrombosis was 0.6 to 1.6%/year. It is concluded that this relatively low inci dence does not warrant life-long continuous use of anti coagulant prophylaxis since the reported risk of major and fatal bleeding associated with the use of oral antico agulants is 2-3 and 0.4%/year, respectively.

Low-molecular-weight heparin has been recommended as the initial treatment of choice for patients with venous thromboembolism who require anticoagulant therapy. In recent studies, outpatient management of these patients has been proposed to be as effective and safe as treatment given in the hospital. This paper outlines the results of these studies and considers the feasibility of home treatment and the consequences of such a strategy. It is concluded that home treatment with low-molecular-weight heparin in patients with venous thromboembolism leads to significant benefits in terms of increase in the quality of life of the patients and a reduction in the duration of hospital stay, thus improving healthcare efficiency.