New oral anticoagulants: appropriateness of prescribing in real‐world setting

BACKGROUND: The new oral anticoagulants (NOAC) have been extensively studied in the clinical trial setting; however, concerns remain about the safety of prescribing in the elderly and patients with renal impairment. AIM: The aim of this study was to assess the appropriateness of NOAC prescribing in a real-world setting in terms of patient selection and to compare patient demographics to those included in pivotal clinical trials. METHODS: One hundred and seventy-six patients from three tertiary university teaching hospitals were identified over 3 months in 2014. RESULTS: Median age of the cohort was 74 years (interquartile range: 61-81 years), with a range of 23-96 years. Overall, 34% of the study population were prescribed a NOAC inappropriately. Of these, treatment was contraindicated in 40%, predominantly due to severe renal impairment, 22% were prescribed an excessively high dose, while 38% were under dosed. Although community-initiated patients had poorer renal function (glomerular filtration rate 91.7 ± 55.7 vs 69.3 ± 38.9, P = 0.024), appropriateness of prescription was no different compared to hospital-initiated patients (78% during admission cf. 61% prior, P = 0.061). Appropriate prescribing was better in patients with venous thromboembolism compared to AF (85% appropriate cf. 60%, P = 0.021). CONCLUSION: Our findings imply that there remains considerable uncertainty about appropriate prescribing and dosing of NOAC, particularly in patients with impaired renal function. We recommend judicious prescribing and regular monitoring of renal function in patients at high risk of complications from NOAC therapy.