BORN to be validated: Assessing agreement between Ontario’s birth registry and CIHI-DAD

Background: The Better Outcomes Registry and Network Ontario Information System (BIS) has captured data on births in Ontario since 2012. Data and information quality is a foundational pillar of Ontario’s birth registry. Objective: To evaluate data quality and reliability, we compared birth data in the BIS with like data elements in the Canadian Institute for Health Information-Discharge-Abstract-Database (CIHI-DAD) which captures administrative, clinical, and demographic data on all hospital discharges. Methods: We used unique pregnancy identifiers to deterministically link maternal records in the BIS to the CIHI-DAD in the fiscal years 2016–2017 to 2020–2021. Percent agreement and Cohen Kappa Coefficients (simple or weighted) with 95% confidence intervals (CI) assessed agreement on selected elements in both databases. Sensitivity analyses explored the impact of the COVID-19 pandemic on data entry and quality processes. Results: There was excellent percentage agreement (⩾90%) between the two databases for all maternal elements assessed. Fourteen out of the twenty elements assessed indicated substantial (κ = 0.61–0.80) or almost perfect agreement (κ = 0.81–0.99) on Kappa tests. Sensitivity analyses restricting the linked cohort to data entered before (2016/2017–2019/2020) and during (2020/2021) the COVID-19 pandemic demonstrated no significant changes in agreement across all elements. Conclusion: Overall, the BIS and CIHI-DAD databases had high agreement on most maternal data elements; however, further examination is necessary to explore discrepancies identified. Implications for health information management practice: As the BIS is newer than the CIHI-DAD and uses a different method of data abstraction, routinely evaluating and enhancing data quality is crucial for providing accurate and valid evidence for health policy, surveillance, and research.