Accuracy of the random glucose test as screening test for gestational diabetes mellitus: a systematic review

Objective

Although not formally supported by guidelines, random glucose testing (RGT) is frequently used to screen for gestational diabetes mellitus (GDM). Results on test accuracy are inconclusive. The aim of this study was to systematically review the literature and calculate summary estimates of accuracy measures of RGT as screening test for GDM.

Study design

Systematic review to identify studies comparing RGT to oral glucose tolerance testing before 32 weeks of pregnancy. A systematic search without language restrictions was performed in MEDLINE (1950 till April 2008) and EMBASE (1980 to April 2008). Study selection and data extraction were performed by two independent reviewers. Outcome measures were summary estimates of test accuracy of RGT.

Results

Six studies were included, reporting on 3537 women. Due to the small number of studies and heterogeneity, no summary estimates of test accuracy were calculated. Reported sensitivities and specificities of individual studies varied. For 100% sensitivity, specificity was around 40%. For sensitivity of 60% specificity was at most 80%. When specificity approached 100%, sensitivity dropped to 20-30%.

Conclusion

Available evidence on the accuracy of RGT to test for GDM is limited. Based on studies in our systematic review, we consider single random glucose measurement inadequate to screen for GDM.