Roy* 1, 2, S. Dhanda1, 2, L. Wise1, S. Shakir1, 2

1Drug Safety Research Unit, Southampton, 2University of Portsmouth, Portsmouth, United Kingdom

Background

The association between oral anticoagulant use and bleeding risk has been widely reported. However, patients may have underlying risk factors which predispose to bleeding. It is valuable to understand the predictors for major bleeding in patients prescribed rivaroxaban.

Objectives

Multivariable logistic regression analyses to explore potential risk factors for major bleeding within gastrointestinal, urogenital and intracranial sites.

Methods

A case/non-case design evaluated the association between clinical risk factors and major bleeding in rivaroxaban patients (N=17546) enrolled to a 12-month cohort study in England (2012-2016). Clinical risk factors for bleeding and bleeding outcomes were collected from general practitioners via questionnaires sent at ≥3, and ≥12 months observation. Multivariable logistic regression analyses examined the association for each site and models were based on two approaches; clinical risk factors selection model and HAS-BLED model. The clinical risk factors selection model included all reported clinical risk factors for bleeding. The HAS-BLED model included HAS-BLED risk score categories (low, moderate, high) and gender. Statistically significant (p<0.05) associations are presented in the results.

Results

Gastrointestinal major bleeds (n=176)

Clinical risk factors selection model

Age 65-74 vs. <65 years OR 2.4 [95% CI 1.3, 4.6]; Age ≥75 vs. <65 years OR 4.2 [95% CI 2.3, 7.5]; Predisposition to/history of bleeding OR 4.8 [95% CI 3.1, 7.5] HAS-BLED model Moderate vs. low OR 4.0 [95% CI 2.1, 7.6]; High vs. low OR 8.9 [95% CI 4.0, 19.9] Urogenital major bleeds (n=36) Clinical risk factors selection model Age 65-74 vs. <65 years OR 0.2 [95% CI 0.1, 0.7]; Female vs. male OR 2.9 [95% CI 1.4, 6.1]; Malignancy OR 2.6 [95% CI 1.1, 6.3] HAS-BLED model Female vs. male OR 2.7 [95% CI 1.3, 5.6] Intracranial major bleeds (n=57) Clinical risk factors selection model Age ≥75 vs. <65 years OR 2.8 [95% CI 1.1, 6.9]; History of cerebrovascular accident (including haemorrhagic)/transient ischaemic attack OR 2.2 [95% CI 1.3, 3.9]; Predisposition to/history of bleeding OR 2.6 [95% CI 1.0, 6.7] HAS-BLED model Moderate vs. low OR 3.3 [95% CI 1.2, 9.1]; High vs. low OR 9.0 [95% CI 2.5, 31.9]

Conclusion

Overall, findings from both models are in keeping with known clinical risk factors for bleeding. For urogenital major bleeds the higher risk in females and younger age group may be related to menstrual bleeding. In clinical practice it is recommended that a bleeding risk assessment, including individual patient characteristics, should be performed prior to anticoagulation.

Disclosure of Interest

The DSRU is an independent charity (No 327206) which works in association with the University of Portsmouth. The DSRU has received funding from Bayer, the manufacturer of Xarelto®. The DSRU makes the final decision on the publication of external communications.