title: Impact of point-of-care international normalized ratio monitoring on quality of treatment with vitamin K antagonists in non-self-monitoring patients: a cohort study.
abstract: BACKGROUND
  Point-of-care (POC) international normalized ratio (INR) monitoring by healthcare professionals could eliminate the need for venous blood sampling in non-self-monitoring (NSM) patients on vitamin K antagonists (VKA). However, few studies have investigated the impact of POC INR monitoring on the quality of treatment in these patients and real-world data on this issue are lacking.
  
  
  OBJECTIVE
  To investigate the safety, efficacy and quality of anticoagulant control during POC INR monitoring as compared with laboratory INR monitoring in NSM patients.
  
  
  METHODS
  We performed a retrospective cohort study using data from the anticoagulation clinic of the Star-Medical Diagnostic Center (Rotterdam, the Netherlands). Patients who received treatment with VKA between 29 May 2012 and 29 May 2014 were eligible. Percentage of time in therapeutic range (TTR) and incidence rates of major clinical events (all-cause mortality, hospitalization, major bleeding and ischemic stroke) were compared for the year before and year after introduction of POC monitoring. Cox proportional hazard models were used to estimate hazard ratios and 95% confidence intervals for major clinical events between exposure groups.
  
  
  RESULTS
  In total, 1973 patients during the 1-year laboratory-monitoring observation period and 1959 patients during the 1-year POC-monitoring observation period were included. Median TTR was significantly lower during POC monitoring (77.9%; 95% CI, 67.2-87.4) than during laboratory INR monitoring (81.0%; 95% CI, 71.1-90.5). Adjusted hazard ratios for major clinical events were all around unity.
  
  
  CONCLUSIONS
  Although associated with lower TTR, POC INR monitoring is a safe and effective alternative to laboratory INR monitoring in NSM patients on VKA.
authors.affiliation: Department of Hematology, Erasmus University Medical Center, Rotterdam, the Netherlands.|Star-Medical Diagnostic Center, Rotterdam, the Netherlands.
authors.forename: J S
authors.initials: JS
authors.lastname: Biedermann
authors.affiliation: Department of Thrombosis and Hemostasis, Leiden University Medical Center, Leiden, the Netherlands.|Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: N
authors.initials: N
authors.lastname: van Rein
authors.affiliation: Department of Thrombosis and Hemostasis, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: A M H P
authors.initials: AM
authors.lastname: van den Besselaar
authors.affiliation: Star-Medical Diagnostic Center, Rotterdam, the Netherlands.
authors.forename: P N
authors.initials: PN
authors.lastname: Buhre
authors.affiliation: Department of Hematology, Erasmus University Medical Center, Rotterdam, the Netherlands.
authors.forename: M P M
authors.initials: MP
authors.lastname: de Maat
authors.affiliation: Department of Thrombosis and Hemostasis, Leiden University Medical Center, Leiden, the Netherlands.
authors.forename: F J M
authors.initials: FJ
authors.lastname: van der Meer
authors.affiliation: Department of Hematology, Erasmus University Medical Center, Rotterdam, the Netherlands.
authors.forename: F W G
authors.initials: FW
authors.lastname: Leebeek
authors.affiliation: Department of Hematology, Erasmus University Medical Center, Rotterdam, the Netherlands.|Star-Medical Diagnostic Center, Rotterdam, the Netherlands.
authors.forename: M J H A
authors.initials: MJ
authors.lastname: Kruip
mesh_terms: D000368:Aged; D000925:Anticoagulants / Q000737:chemistry; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000401:mortality; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis; D006801:Humans; D019934:International Normalized Ratio; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D019095:Point-of-Care Systems; D016016:Proportional Hazards Models; D011787:Quality of Health Care; D015203:Reproducibility of Results; D012189:Retrospective Studies; D016896:Treatment Outcome; D054556:Venous Thromboembolism / Q000188:drug therapy / Q000401:mortality; D014812:Vitamin K / Q000037:antagonists & inhibitors*
chemical_list: D000925:Anticoagulants; D014812:Vitamin K
keywords: anticoagulants; blood coagulation tests; international normalized ratio; point-of-care testing; vitamin K antagonist