title: [Heterogeneity in the handling of vitamin-K-antagonists and of INR: the example of Quercy-Rouergue].
abstract: Using a questionnaire, we have evaluated how VKA and INR are handled by medical doctors in Quercy-Rouergue. This evaluation is part of an international post-analytical quality assessment survey in laboratory medicine supervised by Noklus (http://www.noklus.no/). The original questionnaire designed by Noklus has been adapted to our local practices in replacing warfarin by fluindione. The « Centre de référence et d'éducation aux antithrombotiques d'Ile de France » (Creatif) also participated. Of 282 medical doctors who were sent the questionnaire 109 filled it in, 62% of them being general practitioners. For a target INR at 2.5, the thresholds used to change the dose of VKA range between 1.3 and 2.3 for low values, and between 2.8 and 4 for high values. The bleeding or ischemic risks of being under VKA, versus of not being under VKA, are largely overestimated. INR measurements also tend to be too frequent in stable, and even more so in overdosed, patients. In case of INR at 4.8 only 59% of the participants implement the recommendation of la Haute autorité de santé (HAS) and le Groupe d'étude sur l'hémostase et la thrombose (GEHT) which consists of skipping one dose of VKA, and the attitudes also diverge regarding the importance of the VKA dose reduction, and the number of days under reduced dose before the next INR measurement, the attitude of the Creatif being barely predominant among the participants, and slightly different from that recommended by the HAS and the GEHT. In conclusion, despite the limitations of our methods (the analysis of a questionnaire being less close to the truth than an analysis of actual practices), our evaluation points to the heterogeneity in the knowledge about, and in handling, VKA and INR regarding more particularly management of overdosing, and the estimation of bleeding or ischemic risks, despite the availability of supposedly clear and simple practice guidelines.
authors.affiliation: Laboratoire de biologie polyvalente, Centre hospitalier La Chartreuse, Villefranche-de-Rouergue, France.
authors.forename: Joseph
authors.initials: J
authors.lastname: Watine
authors.affiliation: Unité d'angiologie et d'explorations fonctionnelles vasculaires, Hôpital de Rodez, France.
authors.forename: Wassim
authors.initials: W
authors.lastname: Mokaddem
authors.affiliation: Unité d'angiologie et d'explorations fonctionnelles vasculaires, Hôpital de Rodez, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Carriere
authors.affiliation: Laboratoire de biologie polyvalente, Centre hospitalier de Cahors, France.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Couaillac
authors.affiliation: Laboratory of Clinical Biochemistry, Haukeland University Hospital, Helse Bergen HF, Bergen, Norway.
authors.forename: Ann-Helen
authors.initials: AH
authors.lastname: Kristoffersen
authors.affiliation: Noklus (Norwegian centre for quality improvement of primary care laboratories), University of Bergen, Bergen, Norway.
authors.forename: Geir
authors.initials: G
authors.lastname: Thue
authors.affiliation: Laboratory of Clinical Biochemistry, Haukeland University Hospital, Helse Bergen HF, Bergen, Norway, Noklus (Norwegian centre for quality improvement of primary care laboratories), University of Bergen, Bergen, Norway.
authors.forename: Sverre
authors.initials: S
authors.lastname: Sandberg
mesh_terms: D015110:4-Hydroxycoumarins / Q000627:therapeutic use*; D000368:Aged; D001780:Blood Coagulation Tests / Q000592:standards; D005260:Female; D005602:France / Q000453:epidemiology; D019983:Guideline Adherence / Q000706:statistics & numerical data; D007722:Health Knowledge, Attitudes, Practice; D006761:Hospitals / Q000706:statistics & numerical data; D006801:Humans; D007192:Indenes / Q000627:therapeutic use*; D038622:Internationality; D008297:Male; D008875:Middle Aged; D011364:Professional Practice / Q000592:standards* / Q000706:statistics & numerical data*; D012016:Reference Values; D011795:Surveys and Questionnaires; D014812:Vitamin K / Q000037:antagonists & inhibitors* / Q000627:therapeutic use
chemical_list: D015110:4-Hydroxycoumarins; D007192:Indenes; C011664:antivitamins K; D014812:Vitamin K
keywords: INR; VKA; evaluation; post-analytical; practice guidelines