Accuracy of the drug dependency checkbox on the Maine birth certificate for Medicaid-covered births, 2016-2020

Introduction: The accuracy of the drug dependency checkbox on the Maine birth certificate is unknown. Our objective was to compare the drug dependency checkbox with information on substance use disorders as documented in Medicaid claims data. Methods: Using rule-based deterministic matching, we linked Medicaid enrollment information to 2016-2020 Maine birth record data (N=58,584). Among the linked records (n=27,448), we identified maternal substance use disorder (SUD) diagnoses during the 280 days before through 7 days after delivery using ICD-CM-10 diagnosis codes. We used the following hierarchy to create mutually exclusive SUD categories: opioid use disorder (OUD), cannabis use disorder without cocaine use disorder, and other SUD disorders (alcohol, cocaine, nicotine, or other substance use diagnosis). Results: Among women enrolled in Medicaid at the time of delivery, 12% had drug dependency indicated on their birth record and 33% had at least one SUD diagnosis recorded in their Medicaid claims during pregnancy. Among the birth records with the drug dependency checkbox checked, 56% had an OUD, 25% cannabis use disorder without cocaine use disorder, 8% other SUD, and 10% had no SUD. Among those with the drug dependency checkbox unchecked, the corresponding percentages were 4%, 9%, 13%, and 75%. Discussion: Although diagnoses of OUD and cannabis use disorder were more common among birth records with the drug dependency checkbox checked, reporting of drug dependency on the birth record does not appear to accurately indicate SUD during pregnancy. Conclusions: Our findings suggest the drug dependency checkbox on the Maine birth certificate may be of limited value in identifying SUD during pregnancy.