title: Which point-of-care creatinine analyser for radiology: direct comparison of the i-Stat and StatStrip creatinine methods with different sample types.
abstract: BACKGROUND
  Availability of whole blood creatinine estimation for patients scheduled to undergo radiological contrast investigations can provide information to aid patient care by reducing adverse effects and improving departmental efficiencies.
  
  
  METHODS
  We performed imprecision studies, different patient sample type comparison in 40 participants, and a limited interference study with dopamine and dobutamine on the i-Stat and StatStrip point-of-care enzymatic analysers with the Beckman DxC800 Jaffe assay.
  
  
  RESULTS
  Imprecision results showed that the i-Stat performed better. Patient comparison data indicated that the i-Stat provided better correlation than the StatStrip for all the different sample types with correlation coefficients (r(2)) being 0.995-0.996 and 0.918-0.995, respectively. The i-Stat results had a small positive bias of 6-9% for the three different sample types, which required different reference intervals. The StatStrip method showed greater scatter and overall small negative bias of -6% for the whole blood samples and a 10% positive bias with the plasma samples. Dopamine caused significant positive interference with the i-Stat only while dobutamine caused a small negative bias with the StatStrip method only.
  
  
  CONCLUSIONS
  The findings indicated there are differences offered by the two systems. The StatStrip requires a very small finger prick capillary sample, calculates estimation of the glomerular filtration rate and has an adjustment option to improve correlation with the local method. The i-Stat offers better analytical imprecision and patient comparison with the laboratory method with the three sample types but showed significant interference from dopamine. A final consideration was the availability of middleware to capture patient results with the i-Stat. Based on all the study data, the i-Stat was recommended.
authors.affiliation: Pathology Queensland, Chemical Pathology, Princess Alexandra Hospital, Ipswich Road, Woolloongabba, Brisbane, QLD 4102, Australia. goce_dimeski@health.qld.gov.au
authors.forename: Goce
authors.initials: G
authors.lastname: Dimeski
authors.forename: Vera
authors.initials: V
authors.lastname: Tilley
authors.forename: Brock W
authors.initials: BW
authors.lastname: Jones
authors.forename: Nigel N
authors.initials: NN
authors.lastname: Brown
mesh_terms: D000369:Aged, 80 and over; D057205:Automation, Laboratory / Q000592:standards*; D003404:Creatinine / Q000097:blood*; D004280:Dobutamine / Q000097:blood*; D004298:Dopamine / Q000097:blood*; D004347:Drug Interactions; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019095:Point-of-Care Systems; D011871:Radiology; D012016:Reference Values; D012044:Regression Analysis; D012680:Sensitivity and Specificity
chemical_list: D004280:Dobutamine; D003404:Creatinine; D004298:Dopamine