High persistence and adherence among NOAC users
Adequate persistence and adherence with non-vitamin K antagonists (NOACs) is essential for optimal stroke prevention in atrial fibrillation (AF), but large-scale studies comparing the different NOACs has been lacking.
In a study recently published in Europace, afib.no network member Lars Kjerpeseth was part of a group that investigated persistence and adherence to NOAC treatment among more than half a million AF patients initiating NOAC therapy in Norway, Stockholm (Sweden), Denmark, Scotland and Germany between 2011 and 2018. The follow-up was from the first prescription until a switch to a vitamin K antagonist, emigration, death, end of data availability or the maximum follow-up of 5 years. Persistence and adherence were measured at 3-month intervals the first year of follow-up and then at 6-months intervals. Persistence was defined as the proportion of patients continuing the treatment (i.e. by renewing the prescription). Adequate adherence was defined as the proportion of persistent patients with a medication possession rate (i.e. number of days of drug available divided by the number of days in each interval) of at least 90%.
In total, ~560,000 AF patients were included. Persistence declined to 82% after 1 year and to 63% after 5 years. However, the persistence remained over 80% after 5 years when including restarters of NOAC therapy. Among persistent patients, more than 80% had adequate adherence during follow-up. The persistence and adherence varied little between countries, but were higher in patients starting treatment in later years. After adjusting for patient characteristics, both persistence and adherence were slightly lower with dabigatran compared with apixaban and rivaroxaban.