title: Assessment of psychometric properties of the Brazilian version of the oral anticoagulation knowledge test.
abstract: BACKGROUND
  The aim of this study was to evaluate the psychometric properties of the Brazilian version of the Oral Anticoagulation Knowledge (OAK) Test.
  
  
  METHODS
  This study, conducted in an anticoagulation clinic, included 201 Brazilian participants aged over 18 years, who had been using warfarin for more than two months. The reliability of the instrument was evaluated by assessing internal consistency (Kuder-Richardson coefficient) and reproducibility (test-retest reliability). The validity was evaluated by hypothesizing that there would be a positive correlation of moderate to strong intensity between the correctness levels of the OAK Test and time within therapeutic range (TTR) values, which is a measure used to evaluate the quality of oral anticoagulation.
  
  
  RESULTS
  The instrument exhibited good psychometric properties. The total a Kuder-Richardson coefficient value was 0.818 and intraclass correlation coefficient was 0.967. The validity revealed a strong positive correlation between the values of the level of knowledge, as measured by the OAK Test and the TTR values (rs = 0.780).
  
  
  CONCLUSIONS
  The instrument proved to be a reliable and valid tool for evaluating the knowledge of Brazilian patients on oral anticoagulation therapy with warfarin. This instrument may be incorporated into the practice of health care for substantiating the structuring of educational activities to ensure the improvement of knowledge about the use of warfarin, thereby increasing the effectiveness and safety of treatment.
authors.affiliation: Programa de Pós-Graduação em Medicamentos e Assistência Farmacêutica. Faculdade de Farmácia, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil.
authors.forename: Marcus Fernando da Silva
authors.initials: MF
authors.lastname: Praxedes
authors.affiliation: Departamento de Odontologia Social e Preventiva, Faculdade de Odontologia, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627 Pampulha, CEP 31270-901, Belo Horizonte, MG, Brazil. maurohenriqueabreu@gmail.com.
authors.forename: Mauro Henrique Nogueira Guimarães
authors.initials: MH
authors.lastname: de Abreu
authors.affiliation: Departamento de Odontopediatria e Ortodontia, Faculdade de Odontologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Saul Martins
authors.initials: SM
authors.lastname: Paiva
authors.affiliation: Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Brazil.
authors.forename: Juliana Vaz de Melo
authors.initials: JV
authors.lastname: Mambrini
authors.affiliation: Departamento de Clínica Médica, Faculdade de Medicina, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Milena Soriano
authors.initials: MS
authors.lastname: Marcolino
authors.affiliation: Programa de Pós-Graduação em Medicamentos e Assistência Farmacêutica. Faculdade de Farmácia, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil.
authors.forename: Maria Auxiliadora Parreiras
authors.initials: MA
authors.lastname: Martins
mesh_terms: D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage; D001938:Brazil; D005260:Female; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D014859:Warfarin / Q000008:administration & dosage
chemical_list: D000925:Anticoagulants; D014859:Warfarin
keywords: Anticoagulants; Patient knowledge about medication; Questionnaires; Validation studies