Significance of consecutive international normalized ratio (INR) outcomes using statistical control rules in long-term anticoagulated patients. Optimization of laboratory monitoring and interpretation of borderline measurements

Abstract

AbstractAnalysis of serial measurements is needed to elaborate observations in all fields of medical research. In the present study, retrospective data of anticoagulated patients were used to calculate a mean of observations and control limits, X±1σ and X±2σ (mean±standard deviation). During 18 months of coagulation monitoring, 45 patients without major oral anticoagulant therapy complications, with more international normalized ratio (INR) determinations in the therapeutic range and with a normal distribution of INR values according to the Kurtosis coefficient, were selected. The cumulative distribution functions allowed us to obtain critical limits of INR with a cumulative probability (p). Control limits, calculated for a therapeutic control chart, indicated through different control rules, 1S