Age-dependency of prescribing patterns of oral anticoagulant drugs in Austria during 2011-2014.

Direct oral anticoagulants (DOACs) have been introduced within the last years as alternative to vitamin K antagonists (VKAs) as oral anticoagulant drugs (OAC). The mean/median age of the patients included in DOAC-investigating trials was 70-72 years. The age-pattern of patients to whom DOAC are prescribed in clinical settings is largely unknown. Thus, aim of the study was to assess the age-pattern of patients who received OAC in the years 2011-2014 in Austria. The data analysis refers to the accounting data of the 13 major health insurance funds, covering >97 % of the Austrian population. The number of patients who received OAC in 2011-2014 increased by 43 % (182,464-261,347). Patients who received DOACs increased nearly fivefold (20,927-96,247), whereas patients who received VKAs increased by only 2 % (161,537-165,100). In 2011, the age of patients receiving VKAs was higher than DOACs (72 vs. 68 years), whereas in 2014, the age of the patients receiving VKAs was lower than DOACs (73 vs. 74 years). The proportion of patients ≥80 years receiving VKAs declined from 26 to 21 % of all OAC, receiving DOACs increased from 1 to 12 %. Among nonagenarians, the proportion of patients receiving VKAs remained 2 % (3316-5858), whereas the proportion of patients receiving DOACs increased 40-fold (91-4296). DOACs are prescribed to patients ≥80 years, although there are is a lack of data about efficacy and safety. There is an urgent need for data about this patient group. Since a randomized trial is rather unlikely in this specific age group we suggest subgroup analyses about octo-and nonagenarians, in case they have been included in previously completed or still ongoing trials or registries for OAC.