Deep vein thrombosis (DVT) occurs when a blood clot blocks the flow of blood through a vein, generally in the legs. This can happen after surgery, after trauma, when a person is immobile for a long time, or for no obvious reason. Clots can dislodge and block blood flow to the lungs (pulmonary embolism (PE)), which can be fatal. DVT and PE are known as venous thromboembolism (VTE). Heparin is a blood-thinning drug that is used to treat DVT during the first three to five days. Unfractionated heparin (UFH) is administered intravenously in hospital with laboratory monitoring. Low molecular weight heparins (LMWHs) are given by subcutaneous injection once a day and can be given at home. Oral anticoagulants are then continued for three to six months. After recovery from the acute episode, people may develop post-thrombotic syndrome with leg swelling, varicose veins, and ulceration.
Study characteristics and key results
Seven randomised controlled trials involving 1839 patients with clinically confirmed DVT compared home (LMWH) versus hospital (unfractionated heparin, or LMWH in one trial) treatment. Trials had limitations, including high exclusion rates and designs that did not take into account short hospital stays for any of the people treated at home to allow fair comparison of heparin in hospital with LMWH at home.
Trials showed that patients treated at home with LMWH had less recurrence of VTE than hospital-treated patients. The review showed no clear differences between treatment groups for major bleeding, minor bleeding, or death. No study reported venous gangrene. We could not pool information on patient satisfaction and quality of life, as studies had different ways of reporting these, but two of the three studies reporting on quality of life provided evidence that home treatment led to greater improvement in quality of life compared with in-patient treatment, at some point during follow-up. The third study reported that a large number of participants chose to switch from in-patient care to home-based care for social and personal reasons, indicating that home treatment was better accepted than in-patient treatment. Studies that looked at cost found that cost of home management was lower per incident of treatment.
Quality of the evidence
Overall, the quality of evidence of the available data was low to very low owing to risk of bias, indirectness, and differences in measuring and reporting of outcomes. Risk of bias is a concern, as many of the included studies did not fully explain how they randomised and allocated participants to treatments, and blinding techniques described were not clear. Full blinding would be difficult if not impossible for these types of treatments (home vs hospital), but some techniques could be put in place such as using the same treatment medications or blinding those who measure outcomes. Another concern of reviewers was that in some studies, participants randomised to home treatment actually ended up being treated in hospital but remained in their assigned treatment for the analysis (this is known as indirectness). This makes it hard to determine whether trial results actually can be used to answer the question of whether home versus hospital treatment for DVT is superior. A further concern regarding a few of outcomes is variation in the way outcomes were measured and reported.