RT Journal Article SR Electronic T1 Switching frail older people with AF from a vitamin K antagonist to a DOAC JF Drug and Therapeutics Bulletin JO Drug Ther Bull FD BMJ Publishing Group Ltd SP 115 OP 115 DO 10.1136/dtb.2024.000037 VO 62 IS 8 YR 2024 UL http://dtb.bmj.com/content/62/8/115.abstract AB