Self-reported adherence
The MARS-5 consists of 5 items each addressing intentional non-adherence behaviour. All items are rated on a 5-point Likert Scale from 1 (always) to 5 (never), resulting in a sum scale score of 5 to 25. No standard cut-off value is proposed by the scale developers and cut-off values in the literature have ranged from 20 to 25. Because adherence is of utmost importance in DOAC use and given the lack of monitoring and the poorer clinical outcomes associated with non-adherence a primary cut-off score of <24 to differentiate between non-adherent (score <24) and adherent (score ≥24) patients is used in this study as non-adherence is easily underestimated with the MARS [9]. To evaluate sensitivity of the MARS-5 for assessing adherence to DOACs all analyses will be performed for the MARS-5 cut-off scores of <23 and <25 as well [19,20].