title: Modeling of effect of glucose sensor errors on insulin dosage and glucose bolus computed by LOGIC-Insulin.
abstract: BACKGROUND
  Effective and safe glycemic control in critically ill patients requires accurate glucose sensors and adequate insulin dosage calculators. The LOGIC-Insulin calculator for glycemic control has recently been validated in the LOGIC-1 randomized controlled trial. In this study, we aimed to determine the allowable error for intermittent and continuous glucose sensors, on the basis of the LOGIC-Insulin calculator.
  
  
  METHODS
  A gaussian simulation model with a varying bias (0%-20%) and CV (-20% to +20%) simulated blood glucose values from the LOGIC-1 study (n = 149 patients) in 10 Monte Carlo steps. A clinical error grid system was developed to compare the simulated LOGIC-Insulin-directed intervention with the nominal intervention (0% bias, 0% CV). The severity of error measuring the clinical effect of the simulated LOGIC-Insulin intervention was graded as type B, C, and D errors. Type D errors were classified as acutely life-threatening (0% probability preferred).
  
  
  RESULTS
  The probability of all types of errors was lower for continuous sensors compared with intermittent sensors. The maximum total error (TE), defined as the first TE introducing a type B/C/D error, was similar for both sensor types. To avoid type D errors, TEs <15.7% for intermittent sensors and <17.8% for continuous sensors were required. Mean absolute relative difference thresholds for type C errors were 7.1% for intermittent and 11.0% for continuous sensors.
  
  
  CONCLUSIONS
  Continuous sensors had a lower probability for clinical errors than intermittent sensors at the same accuracy level. These simulations demonstrated the suitability of the LOGIC-Insulin control system for use with continuous, as well as intermittent, sensors.
authors.affiliation: Department of Intensive Care Medicine, University Hospitals Leuven, Katholieke Universiteit Leuven, Leuven, Belgium; Department of Electrical Engineering (ESAT-SCD), iMINDS Medical Information Technologies, Katholieke Universiteit Leuven, Leuven (Heverlee), Belgium. tom.vanherpe@esat.kuleuven.be.
authors.forename: Tom
authors.initials: T
authors.lastname: Van Herpe
authors.affiliation: Department of Electrical Engineering (ESAT-SCD), iMINDS Medical Information Technologies, Katholieke Universiteit Leuven, Leuven (Heverlee), Belgium.
authors.forename: Bart
authors.initials: B
authors.lastname: De Moor
authors.affiliation: Department of Intensive Care Medicine, University Hospitals Leuven, Katholieke Universiteit Leuven, Leuven, Belgium;
authors.forename: Greet
authors.initials: G
authors.lastname: Van den Berghe
authors.affiliation: Department of Intensive Care Medicine, University Hospitals Leuven, Katholieke Universiteit Leuven, Leuven, Belgium;
authors.forename: Dieter
authors.initials: D
authors.lastname: Mesotten
mesh_terms: D000465:Algorithms; D001774:Blood Chemical Analysis; D001786:Blood Glucose / Q000032:analysis*; D003198:Computer Simulation; D054796:Drug Dosage Calculations; D006801:Humans; D007328:Insulin / Q000008:administration & dosage* / Q000097:blood*
chemical_list: D001786:Blood Glucose; D007328:Insulin