A Cochrane review [Abstract] 1 included 5 studies with a total of 1 508 patients. One of the five included studies included people with pulmonary embolism (PE) and deep vein thrombosis (DVT), the other 4 studies included only people with DVT. The 5 included studies used 4 brands of low molecular weight heparin (LMWH) (enoxaparin, tinzaparin, dalteparin and nadroparin). The pooled data showed no difference in recurrent venous thromboembolism (OR 0.82, 95% CI 0.49 to 1.39; 3 studies, n=1 281) or extension of thrombus size (OR 1.41, 95% CI 0.66 to 3.01; 2 studies, n=107) between once versus twice daily LMWH for the initial treatment of venous thromboembolism. There were no significant differences in major haemorrhagic events (OR 0.77, 95% CI 0.40 to 1.45; 5 studies, n=1 508) and mortality (OR 1.14; 95% CI 0.62 to 2.08; 4 studies, n=1 421) between the two treatment regimens. None of the 5 included studies reported data on post-thrombotic syndrome.
Comment: The quality of evidence is downgraded by study quality (inadequate or unclear allocation concealment).
Primary/Secondary Keywords