Background Evidence regarding use of direct oral anticoagulants (DOACs) in the elderly, particularly bleeding risks, is unclear despite the presence of greater comorbidities, polypharmacy and altered pharmacokinetics in this age group. Methods and Results We performed a systematic review and meta-analysis of randomised trials of DOACs (dabigatran, apixaban, rivaroxaban, edoxaban) for efficacy and bleeding outcomes compared to VKA (vitamin k antagonists) in elderly participants (aged ≥75 years) treated for acute venous thromboembolism or stroke prevention in atrial fibrillation. Nineteen studies were eligible for inclusion but only 11 reported data specifically for elderly participants. Efficacy in managing thrombotic risks for each DOAC was similar or superior to VKA in the elderly. A non-significantly, higher risk of major bleeding than VKA was observed with dabigatran 150mg (Odds Ratio 1.18, 95% confidence interval 0.97-1.44) but not with the 110mg dose. Significantly higher gastrointestinal bleeding risks with dabigatran 150mg (1.78, 1.35-2.35) and 110mg (1.40, 1.04-1.90) and lower intracranial bleeding risks than VKA for dabigatran 150mg (0.43, 0.26-0.72) and dabigatran 110mg (0.36, 0.22-0.61) were also observed. A significantly lower major bleeding risk compared to VKA was observed for apixaban (0.63, 0.51-0.77), edoxaban 60mg (0.81, 0.67-0.98) and 30mg (0.46, 0.38-0.57) while rivaroxaban showed similar risk. Conclusion DOACs demonstrated at least equal efficacy to VKA in managing thrombotic risks in the elderly however bleeding patterns were distinct. In particular, dabigatran was associated with a higher risk of gastrointestinal bleeding than VKA. Insufficient published data for apixaban, edoxaban and rivaroxaban indicates further work is needed to clarify their bleeding risks in the elderly.

Summary. Background: Non-adherence to prescribed medication represents a significant factor associated with treatment failure. Pregnant women identified at risk of venous thromboembolism are increasingly being prescribed low-molecularweight heparin (LMWH) during pregnancy and the puerperium. It is important to understand womenÕs views on and adherence to LMWH during pregnancy and the puerperium, so that women gain maximum benefit from the treatment. Objectives: To monitor womenÕs adherence to enoxaparin, when prescribed during pregnancy and the puerperium, and explore their beliefs about the enoxaparin therapy prescribed. Patients/ Methods: A prospective cohort study involving 95 nullparous and multiparous women prescribed enoxaparin for recognized antenatal indications. Adherence to enoxaparin was assessed through self-completion of a diary, additionally verified through laboratory tests. An adapted beliefs about medication questionnaire was administered to women during their pregnancy. Results: Women were highly adherent to enoxaparin: antenatally, mean percentage adherence 97.92%; postnatally, mean percentage adherence 93.37% (paired t-test, P = 0.000). In the cohort of women we followed, their perceived necessity for enoxaparin therapy outweighed any concerns they had regarding enoxaparin antenatally, necessity-concerns differential 2.20. In some women, however, this perceived necessity does decrease postnatally. Conclusions: Our results suggest that most women prescribed enoxaparin are highly adherent to their therapy during the antenatal period and that womenÕs antenatal beliefs about enoxaparin are able to predict a decrease in postnatal adherence. Our results have important clinical implications, particularly when women are initiated on LMWH just during the postnatal period.