title: Constant use of oral anticoagulants: implications in the control of their adequate levels.
abstract: BACKGROUND
  Inappropriate and subtherapeutic anticoagulants dosages may result in severe thromboembolic and bleeding complications. The use of this treatment requires special attention and strict clinical and laboratory follow-up.
  
  
  OBJECTIVE
  To identify factors associated with appropriate control of the oral anticoagulant use, assessing the patients' knowledge and perception of the treatment.
  
  
  METHODS
  A cross-sectional study which included 140 patients followed in the oral anticoagulation outpatient clinic from November 2005 to June 2006. A structured questionnaire was drafted and applied to obtain the clinical characteristics of the patients and their knowledge about the treatment, their compliance with the treatment (Morisky s test) and their perception of the treatment.
  
  
  RESULTS
  The main indications for the use of oral anticoagulation therapy were atrial fibrillation (61.4%) and a prosthetic heart valve (55%). The duration of anticoagulation ranged from 24 to 72 months, and phenprocoumon (58%) was the most commonly used anticoagulant. As to the perception of the treatment, 95% of the patients mentioned concern about daily use of this medication. Periodic blood tests (21.4%) and the strict intake of oral anticoagulant (12.8%) were considered limiting factors. Adequate knowledge was outstanding in patients with an international normalized ratio (INR) outside the therapeutic range (64%), compared to patients with an INR within the therapeutic range (62%), as well as compliance with treatment in patients with an INR within the therapeutic range (54%), but with no statistical significance.
  
  
  CONCLUSIONS
  The results of this study show a prevalence of patients using oral anticoagulant with an INR within optimal values, although a high percentage of patients do not comply with the treatment. In this population it is clearly seen that they do not fully understand the treatment.
authors.affiliation: Instituto de Cardiologia do Rio Grande do Sul, Fundação Universitária de Cardiologia, Porto Alegre, RS, Brasil.
authors.forename: Francieli Giachini
authors.initials: FG
authors.lastname: Esmerio
authors.forename: Emiliane Nogueira
authors.initials: EN
authors.lastname: Souza
authors.forename: Tiago Luz
authors.initials: TL
authors.lastname: Leiria
authors.forename: Rosana
authors.initials: R
authors.lastname: Lunelli
authors.forename: Maria Antonieta
authors.initials: MA
authors.lastname: Moraes
mesh_terms: D000284:Administration, Oral; D000925:Anticoagulants / Q000008:administration & dosage*; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000523:psychology*; D003430:Cross-Sectional Studies; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006349:Heart Valve Diseases / Q000188:drug therapy / Q000523:psychology*; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D016903:Drug Monitoring
chemical_list: D000925:Anticoagulants