Reviewing performance of birth certificate and hospital discharge data to identify births complicated by maternal diabetes.

OBJECTIVES

Public health surveillance of diabetes during pregnancy is needed. Birth certificate and hospital discharge data are population-based, routinely available and economical to obtain and analyze, but their quality has been criticized. It is important to understand the usefulness and limitations of these data sources for surveillance of diabetes during pregnancy.

METHODS

We conducted a comprehensive literature review to summarize the validity of birth certificate and hospital discharge data for identifying diabetes-complicated births.

RESULTS

Sensitivities for birth certificate data identifying prepregnancy diabetes mellitus (PDM) ranged from 47% to 52%, median 50% (kappas: min = 0.210, med = 0.497, max = 0.523). Sensitivities for birth certificate data identifying gestational diabetes mellitus (GDM) ranged from 46% to 83%, median 65% (kappas: min = 0.545, med = 0.667, max = 0.828). Sensitivities for the two studies using hospital discharge data for identifying PDM were 78% and 95% (kappas: 0.839 and 0.964), and for GDM were 71% and 81% (kappas: 0.584 and 0.840). Specificities were consistently above 98% for both data sources.

CONCLUSIONS

Overall, hospital discharge data performed better than birth certificates, marginally so for identifying GDM but substantially so for identifying PDM. Reports based on either source alone should focus on trends and disparities and include the caveat that results under represent the problem. Linking the two data sources may improve identification of both GDM and PDM cases.