title: Critical evaluation of connectivity-based point of care testing systems of glucose in a hospital environment.
abstract: BACKGROUND
  In recent years a number of point of care testing (POCT) glucometers were introduced on the market. We investigated the analytical variability (lot-to-lot variation, calibration error, inter-instrument and inter-operator variability) of glucose POCT systems in a university hospital environment and compared these results with the analytical needs required for tight glucose monitoring.
  
  
  METHODS
  The reference hexokinase method was compared to different POCT systems based on glucose oxidase (blood gas instruments) or glucose dehydrogenase (handheld glucometers). Based upon daily internal quality control data, total errors were calculated for the various glucose methods and the analytical variability of the glucometers was estimated.
  
  
  RESULTS
  The total error of the glucometers exceeded by far the desirable analytical specifications (based on a biological variability model). Lot-to-lot variation, inter-instrument variation and inter-operator variability contributed approximately equally to total variance. As in a hospital environment, distribution of hematocrit values is broad, converting blood glucose into plasma values using a fixed factor further increases variance. The percentage of outliers exceeded the ISO 15197 criteria in a broad glucose concentration range.
  
  
  CONCLUSIONS
  Total analytical variation of handheld glucometers is larger than expected. Clinicians should be aware that the variability of glucose measurements obtained by blood gas instruments is lower than results obtained with handheld glucometers on capillary blood.
authors.affiliation: Department of Clinical Chemistry, University Hospital Ghent, Ghent, Belgium.
authors.forename: Katelijne M J
authors.initials: KM
authors.lastname: Floré
authors.forename: Tom
authors.initials: T
authors.lastname: Fiers
authors.forename: Joris R
authors.initials: JR
authors.lastname: Delanghe
mesh_terms: D001786:Blood Glucose / Q000032:analysis*; D015190:Blood Glucose Self-Monitoring / Q000295:instrumentation / Q000592:standards*; D042843:Glucose 1-Dehydrogenase / Q000097:blood; D005949:Glucose Oxidase / Q000097:blood; D006801:Humans; D007755:Laboratories, Hospital / Q000592:standards*; D019095:Point-of-Care Systems / Q000592:standards*; D011786:Quality Control
chemical_list: D001786:Blood Glucose; D042843:Glucose 1-Dehydrogenase; D005949:Glucose Oxidase