Structured Reporting and Reflex Confirmation Enhance Toxicology Oversight in Perinatal Urine Drug Screening: A Six-Month Institutional Review

Background: Urine drug screening (UDS) plays a critical role in identifying both therapeutic and non-prescribed drug exposures, particularly in obstetric patients and their neonates. While immunoassay-based platforms provide rapid screening capabilities, they are limited by potential cross-reactivity and false positives. In October 2023, our institution implemented a scheduled reporting protocol alongside universal maternal screening using the Drug Abuse Screening Test-10 (DAST-10), a validated questionnaire for assessing substance use risk. This approach ensured all patients were screened consistently at the time of admission, helping to minimize subjectivity and support standardized, equitable care delivery. Methods: We conducted a retrospective post-implementation review covering January to June 2025, evaluating UDS and confirmation patterns among obstetric inpatients. Data collected included the number of total tests, abnormal results, drug classes identified, whether confirmatory testing was conducted, and concordance between screening and confirmation. Provider documentation and maternal DAST-10 screening responses were reviewed to assess the clinical context of testing decisions. Results: A total of 81 UDS tests were completed during the review period. Forty tests (49%) were abnormal, of which 18 were associated with known prescribed medications and did not require confirmatory testing. Confirmatory testing was performed in 22 cases, with 14 (64%) concordant and 8 (36%) discordant with the initial UDS. Discordance was attributed to the timing of sample collection post-medication, potential cross-reactivity, or insufficient documentation to support testing. Conclusion: One year after implementing standardized DAST-10 screening and updated biologic testing guidelines, our data suggest improved appropriateness in confirmatory test utilization. The persistence of discordant results underscores the limitations of point-of-care immunoassays and highlights the need for thoughtful clinical correlation. Unlike earlier audits, this focused post-implementation review shows sustained adherence and emphasizes the need for ongoing education, audit feedback, and EMR optimization to minimize unnecessary testing and bias.