In clinical trials the new oral anticoagulants (NOACs) have been shown to have similar efficacy and safety compared to warfarin, but questions have been raised about whether the results are similar in real world settings.

Now a new observational study lends some measure of reassurance that the new drugs are not associated with increased bleeding risks.

Researchers in Canada performed a retrospective, matched cohort study analysing data from 59,525 venous thromboembolism (VTE) patients in 6 separate healthcare systems in the US and Canada. They compared 12,489 patients taking one of the NOACs with 47,036 warfarin users. The vast majority (94.9% of the NOAC group were taking rivaroxaban.

Overall 1.7% of the study subjects died and 3.3% had a major bleed. At 30 days the bleeding rate was 2.9% for warfarin and ranged between 0.2% and 2.9% for the NOACs.

At 60 days the bleeding rates were 4.3% for warfarin and ranged between 0.4% and 4.3% for the NOACs.

The hazard ratio for major bleeding for NOAC use compared with warfarin use was 0.92 (CI 0.82-1.03).

There was also no significant difference in mortality (HR 0.99) and there were no significant differences based on age, sex, or whether or not patients had chronic kidney disease.

NOACs, the writers conclude in their BMJ paper, “show no increased risk of gastrointestinal bleeding associated” with NOAC use.”

The findings suggest that NOACs “may be considered as a treatment option for patients with venous thromboembolism who are candidates for anticoagulation,” the authors concluded.

But, they cautioned, since it is an observational study they were unable, of course, to fully eliminate the possibility of residual confounding.

This article has been republished from Larry’s blog CardioBrief as part of a licensing agreement between Everyday Health and the limbic.