Did publication of a clinical practice guideline recommendation to screen for type 2 diabetes in women with gestational diabetes change practice?

OBJECTIVE - To determine whether women with previous gestational diabetes mellitus (GDM) were screened postpartum for type 2 diabetes according to the Canadian Diabetes Association (CDA) guidelines. RESEARCH DESIGN AND METHODS - The 1998 CDA guidelines recommend that all women diagnosed with GDM be screened postpartum for type 2 diabetes using a 2-h 75-g oral glucose tolerance test (OGTT). The impact of and compliance with this expert opinion-based recommendation is unknown. All women who delivered at the Ottawa Hospital in 1997 (preguideline) and 2000 (post-guideline) with confirmed GDM were identified. Using population-based administrative databases, we determined the proportion of these women who had an OGTT, serum glucose test, or glycated hemoglobin (GHb) test in the first postpartum year. Women who had not undergone any blood work were excluded. RESULTS - There were 131 women in 1997 and 123 women in 2000 with confirmed GDM. Of these, only 69 women in 1997 and 52 women in 2000 had blood work recorded in the database. None of these women had an OGTT performed in either period. We found a significant increase in the measurement of serum glucose (50 women pre-guideline [72.1%], 48 women post-guideline [92.3%], P < 0.05) and GHb (8 women pre-guideline [11.6%], 20 women post-guideline [38.5%], P < 0.01). CONCLUSIONS - in our region, physicians are not following the CDA recommendations to screen women with GDM postpartum with an OGTT. However, we did find a significant increase in the measurement of serum glucose and GHb. Publication of expert opinion-based guidelines did not change the postpartum use of an OGTT in these women but may have increased the use of less reliable screening tests for type 2 diabetes.