Fig. 2.

Diagram of flow and type of data from each source. 1a) EHR data flows from MPCA member health centers to central data repository with Azara Healthcare; 26 health centers approved use of data for this study. 1b) Claims data flows from Missouri Medicaid (fee for service and managed care plans) to the Office of Social and Economic Data Analysis (OSEDA). 2) De-identified EHR data from women with pregnancy related codes 1/1/2010–12/31/2015 sent to Washington University (demographics, encounter data, charges, payer information, medications/supplies ordered, laboratory data, infant birthweight (if available), and delivery date (if available) - delivery date and codes related to comorbidities and complications were limited. 3) Potential gestational diabetes candidates identified based on combination of ICD-9/10-CM codes, medication and supply data, laboratory data, and infant birthweight – randomly generated number ID for potential gestational diabetes candidates transferred back to Azara Healthcare. 4) Azara Healthcare transferred Medicaid identifier, first name, last name, date of birth, zip code and phone number with randomly generated number ID to OSEDA for linking with claims data from ‘potential gestational diabetes candidates’ with delivery date 1/1/2010–12/31/2015; Address on these individuals was transferred separately to Washington University for creation of geographic variables. 5) OSEDA transferred randomly generated number ID with linked inpatient and outpatient claims to Washington University (included medical eligibility code, place of service code, revenue codes, provider specialty code, National Provider Identifier, provider type code, and dates of service with ICD-9/10-CM diagnosis, ICD-9-CM/ICD-10-Procedure Coding System (PCS) procedure codes, and CPT-4 codes). 6) Washington University narrows the population to women with probable gestational diabetes defined by ICD-9/10-CM code or Carpenter and Coustan laboratory criteria based on defining delivery date, period of gestation, and postpartum period