Screening for gestational diabetes mellitus with a reflectance photometer: Accuracy and precision of the single-operator model

N. J. Murphy, B. A. Meyer, R. T. O'Kell, M. E. Hogard

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Objective: To investigate the accuracy and precision of a recent-generation reflectance photometer, Accu-Chek III, for gestational diabetes mellitus screening with a single operator. Methods: Four hundred ten paired capillary and serum glucose samples collected prospectively were evaluated by a reflectance photometer and a glucose oxidase method (Beckman), respectively, during routine gestational diabetes mellitus screening with a single operator. Results: The mean Accu-Chek III result was 12% greater than serum glucose oxidase (115.5±1.4 and 103.4±1.3 mg/dL, respectively). A serum glucose level of at least 135 mg/dL by glucose oxidase produced sensitivity and specificity of 0.81 and 0.68, respectively. At 155 mg/dL, the Accu-Chek III sensitivity was 0.81 and specificity 0.74, and the method produced fewer false-positive results (37 of 410 [9.0%] versus 41 of 410 [10%]) than a 135-mg/dL serum cutoff. Adjusting the Accu-Chek III threshold by two times the coefficient of variation resulted in the same number of false positives as the Beckman technique at 135 mg/dL. The receiver operating characteristic curve cutoff for the venous value of 135 mg/dL was an Accu-Chek III value of 141 mg/dL. Linear regression analysis predicted y=20.6+0.919x, r=0.838. The mean coefficient of variation was 3.9%. Conclusions: The Accu-Chek III produced accurate and precise gestational diabetes mellitus screening results with a single operator. Because capillary blood is a combination of arterial and venous blood, an Accu-Chek III cutoff of 155 mg/dL may be more appropriate for screening, considering the 10-15% higher capillary glucose level in the fed state. An Accu-Chek III cutoff of 155 mg/dL produced a higher specificity than venous serum at 135 mg/dL, with no decrease in sensitivity.

Original languageEnglish (US)
Pages (from-to)1038-1042
Number of pages5
JournalObstetrics and Gynecology
Issue number6
Publication statusPublished - 1994


ASJC Scopus subject areas

  • Obstetrics and Gynecology

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