title: Clinical evaluation of a novel on-strip calibration method for blood glucose measurement.
abstract: This study evaluated a novel technology for improving accuracy of self-monitoring of blood glucose (SMBG). The technology calibrates each and every test by measuring the response from a predetermined amount of glucose present in the sample chamber of each test strip. SMBG test strips were modified to include a lid coated with a fast dissolving formulation containing glucose. These test strips were characterized for hematocrit (Hct) and temperature induced error response to develop a calibration algorithm. The modified test strips were used in a clinical evaluation involving fingerstick blood samples from 160 subjects. Experiments involving Hct and temperature induced errors show that the technology generates a signal characteristic of the error conditions in any particular test, but independent of glucose concentration, allowing a correction algorithm to be derived. The approach substantially reduced Hct and temperature derived errors. Clinical evaluation using fingerstick blood directly applied to prototype strips showed the error (measured as MARD) was reduced from 11.1 to 5.9% by the on-strip correction approach and the number of outliers reduced by approximately 90%. This technology could improve the accuracy and precision of glucose monitoring systems and so reduce decision errors particularly in clinical situations where hematocrit and temperature may be significant confounders.
authors.affiliation: Exacsys Ltd, Cambridge Technology Centre, Melbourn, UK michael.noble@exacsys.co.uk.
authors.forename: Michael
authors.initials: M
authors.lastname: Noble
authors.affiliation: Exacsys Ltd, Cambridge Technology Centre, Melbourn, UK.
authors.forename: John
authors.initials: J
authors.lastname: Rippeth
authors.affiliation: Exacsys Ltd, Cambridge Technology Centre, Melbourn, UK.
authors.forename: David
authors.initials: D
authors.lastname: Edington
authors.affiliation: Ipswich Hospital NHS Trust, Diabetes Research Centre, Ipswich Hospital National Health Service Trust, Suffolk, UK.
authors.forename: Gerry
authors.initials: G
authors.lastname: Rayman
authors.affiliation: PA Consulting Group, Cambridge Technology Centre, Melbourn, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Brandon-Jones
authors.affiliation: PA Consulting Group, Cambridge Technology Centre, Melbourn, UK.
authors.forename: Zoe
authors.initials: Z
authors.lastname: Hollowood
authors.affiliation: PA Consulting Group, Cambridge Technology Centre, Melbourn, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Kew
mesh_terms: D000465:Algorithms; D001786:Blood Glucose / Q000032:analysis*; D015190:Blood Glucose Self-Monitoring / Q000295:instrumentation* / Q000379:methods; D002138:Calibration; D006400:Hematocrit; D006801:Humans; D011934:Reagent Strips; D015203:Reproducibility of Results; D013696:Temperature
chemical_list: D001786:Blood Glucose; D011934:Reagent Strips
keywords: accuracy; blood glucose monitoring; error; hematocrit