Evaluation of an active population-based surveillance system for major birth defects in South Carolina.

Introduction: Birth defects are common, costly, and contribute substantially to infant mortality. The South Carolina Birth Defects Program (SCBDP) employs active population-based surveillance to monitor major birth defects statewide. We evaluated SCBDP's system attributes using published CDC guidelines.

Methods: To determine timeliness, completeness, and accuracy of birth defects information, we examined SCBDP's reports, program and education materials, advisory group meeting minutes, and strategic plan. We also met with program staff and stakeholders (n = 10) to discuss program goals and data utilization. We calculated the percentage of birth defects cases found 6 months after a birth cohort year for 2016-2018.

Results: SCBDP identifies 900-1,200 birth defects cases for a birth population of approximately 55,000 live births annually through active case reviews. SCBDP uses trained medical staff to abstract detailed information from maternal and infant medical records; SCBDP also has established auto-linkage with state vital statistics to capture demographic and birth data. SCBDP is timely and captures 97.1% (range 96.7-97.6%) of birth defects cases within 6 months after the birth cohort year closes. Active case identification using medical records as the primary data source improves quality assurance and completeness, while prepopulating demographic information improves timeliness.

Conclusions: Given that birth defects significantly contribute to infant morbidity and mortality, monitoring these conditions is important to understand their impact on communities and to drive public health actions. SCBDP active surveillance and rigorous data quality practices provide the program with timely, complete, and accurate birth defects data.