Reasons for Undertreatment with Oral Anticoagulants in Frail Geriatric Outpatients with Atrial Fibrillation A Prospective, Descriptive Study Linda R. Tulner, 1 Jos P.C.M. Van Campen, 1 Ingeborg M.J.A. Kuper, 1 George J.P.T. Gijsen, 1,2 Cornelis H.W. Koks, 2 Melvin R. Mac Gillavry, 3 Harm van Tinteren, 4 Jos H. Beijnen 2,5 and Desiderius P.M. Brandjes 6 1 Department of Geriatric Medicine, Slotervaart Hospital, Amsterdam, the Netherlands 2 Department of Pharmacy & Pharmacology, Slotervaart Hospital, Amsterdam, the Netherlands 3 Department of Cardiology, Slotervaart Hospital, Amsterdam, the Netherlands 4 Biometrics Department, Netherlands Cancer Institute – Antoni van Leeuwenhoekhuis, Amsterdam, the Netherlands 5 Beta Faculty Department of Pharmaceutical Sciences, Division of Drug Toxicology, Utrecht University, Utrecht, the Netherlands 6 Department of Internal Medicine, Slotervaart Hospital, Amsterdam, the Netherlands Abstract Objectives: The main aims of the study were to explore whether oral anti- coagulation (OAC) for atrial fibrillation (AF) in geriatric outpatients is pre- scribed in accordance with international (American College of Cardiology/ American Heart Association/European Society of Cardiology [ACC/AHA/ ESC]) and Dutch national guidelines for the general practitioner (GP) and to identify whether age and selected co-morbid conditions are associated with undertreatment. As a secondary objective, we wanted to establish how many patients discontinue OAC because of major bleeding. Methods: In 2004, at the first visit of all patients to the geriatric day clinic of the Slotervaart Hospital in Amsterdam, the Netherlands, demographic data, Mini- Mental State Examination score, medical history, Charlson Comorbidity Index score, and data on medication use and changes were documented. The presence of AF was established by assessment of medical history information obtained by the GP, the history taken from patients and their caregivers, and the results of clinical evaluation, including ECG findings. Associations between the use of OAC, demographic data and co-morbid conditions registered in the Dutch NHG (Nederlands Huisartsen Genootschap [Dutch College of General Prac- titioners]) standard for GPs as risk factors for stroke or contraindications to the use of OAC were analysed. The reasons for discontinuing OAC were assessed after 4 years by requesting the information from the anticoagulation services or the GP. ORIGINAL RESEARCH ARTICLE Drugs Aging 2010; 27 (1): 39-50 1170-229X/10/0001-0039/$49.95/0 ª 2010 Adis Data Information BV. All rights reserved.