Comparison of accuracy measures of two screening tests for gestational diabetes mellitus

doi:10.2337/dc07-0571

Comparison of accuracy measures of two screening tests for gestational diabetes mellitus

Marsha van Leeuwen, MD (Marsha.vanLeeuwen{at}amc.uva.nl)¹,
Egbert J.K. Zweers, MD^2,,³,
Brent C. Opmeer, MD, PhD⁴,
Evert van Ballegooie, MD, PhD^5,,⁶,
Henk G. ter Brugge, MD⁷,
Harold W. de Valk, MD, PhD²,
Ben W.J. Mol, MD, PhD^8,,⁹ and
Gerard H.A. Visser, MD, PhD, Professor⁸

¹ Obstetrics and Gynaecology, Academic Medical Centre, Amsterdam, The Netherlands
² Internal Medicine, University Medical Centre, Utrecht, The Netherlands
³ Internal Medicine, Bronovo Hospital, The Hague, The Netherlands
⁴ Clinical Epidemiology and Biostatistics, Academic Medical Centre, Amsterdam, The Netherlands
⁵ Internal Medicine, Isala Clinics, Zwolle, The Netherlands
⁶ Internal Medicine, Bethesda Hospital, Hoogeveen, The Netherlands
⁷ Obstetrics and Gynaecology, Isala Clinics, Zwolle, The Netherlands
⁸ Perinatology and Gynaecology, University Medical Center, Utrecht, The Netherlands
⁹ Obstetrics and Gynaecology, Máxima Medical Centre, Veldhoven, The Netherlands

Abstract

Objective To compare the accuracy measures of the random glucose test and the 50 g glucose challenge test as screening tests for gestational diabetes mellitus.

Research design and methods In this prospective cohort study pregnant women without pre-existing diabetes mellitus in two perinatal centres in The Netherlands underwent a random glucose test and a 50 g glucose challenge test between 24 and 28 weeks of gestation. If one of the screening tests exceeded predefined threshold values, the 75 g oral glucose tolerance test (OGTT) was performed within one week. Furthermore the OGTT was performed in a random sample of women in whom both screening tests were normal. Gestational diabetes was considered present when the OGTT (reference test) exceeded predefined threshold values. Receiver operating characteristic analysis was used to evaluate the performance of the two screening tests. The results were corrected for verification bias.

Results We included 1301 women. The OGTT was performed in 322 women. After correction for verification bias, the random glucose test showed an area under the ROC curve (AUC) of 0.69 (95% CI 0.61 to 0.78) whereas the glucose challenge test had an AUC of 0.88 (95% CI 0.83 to 0.93). There was a significant difference in area under the curve of the two tests of 0.19 (95% CI 0.11 to 0.27) in favour of the 50 g glucose challenge test.

Conclusions In screening for gestational diabetes mellitus, the 50 g glucose challenge test is more useful than the random glucose test.