Evaluation of a mobile electronic assistant to aid in fluindione prescription: the INRPlus cluster randomized trial.

Introduction: Regular monitoring of the international normalized ratio (INR) is crucial for dose adjustment of vitamin K antagonists (VKA) to maximize time in therapeutic range (TTR). We compared the use of a mobile electronic assistant INRPlus which proposes patient-specific fluindione doses, to standard fluindione management in a cluster randomized controlled study.
Patients and Methods: Twenty clusters of six general practitioners were randomized to adjust fluindione doses in VKA-treated patients either using INRPlus or according to routine practice. TTR was measured over 6 months, along with time spent above or below the recommended INR range, frequency of measurements and related complications.
Results: Of the 595 included patients, 551 were assessable (259 INRPlus, 292 control) and had a mean of 1.6 INR measurements/month. TTR was not significantly different between the two groups, 72.7% [Q1: 58.1%; Q3: 90%] in INRPlus patients and 71.2% [Q1: 54.8%; Q3: 88.2%] in control patients (p=0.445). At least 60% time within reference ranges was reported in 73.4% of INRPlus patients and 67.1% of control patients (relative risk 1.09, 95%CI 0.98-1.22, p=0.115). No significant differences were reported between the two groups for time outside reference ranges, frequency of measurements or complications. Eighty-two percent (82%) of patients complying with INRPlus-proposed doses spent more than 60% of TTR versus 66.9% of non-compliant patients and 67.1% of reference patients.
Conclusions: In this trial, the use of the INRPlus electronic assistant resulted in a non-significant improvement in TTR that may be due to a higher than expected TTR in the control group.
(Copyright © 2014 Elsevier Ltd. All rights reserved.)