Pregestational Diabetes Exposure in Utero: Validation of a Definition for Use in Administrative Data

Objective: Our aim in this study was to determine the best administrative data case definition for pregestational diabetes exposure. Methods: We compared the performance of case definitions for pregestational diabetes exposure within the administrative health data housed in the Manitoba Population Health Research Repository at the Manitoba Centre for Health Policy with an identified population of women in whom the diagnosis of pregestational diabetes was known from the clinical database of the Manitoba Diabetes Education Resource for Children and Adolescents (DER-CA) (August 12, 1989 through January 28, 2015). The DER-CA database contains maternal diabetes status during pregnancy and also includes women diagnosed with type 2 diabetes in childhood whose pregnancies were thus all complicated by pregestational diabetes exposure. Linkage of mother-child dyads is possible within the Repository. Diagnosis codes from the International Classification of Diseases-ninth or tenth revision and physician tariff codes were used to identify diabetes in the biologic mothers of children with type 2 diabetes identified from the DER-CA database. The timing of the diagnosis of diabetes in the mother with respect to the gestational age of the pregnancy was determined. Results: The best administrative definition of pregestational diabetes exposure was any incident code for diabetes in the mother before the pregnancy of the index child or within the first 25 weeks of pregnancy (sensitivity: 84.77%; positive predictive value: 92%). Conclusion: The definition cited can be used to define pregestational diabetes exposure in studies utilizing administrative data. (C) 2021 Canadian Diabetes Association.