Toward Successful International Pooling of Breast Implant Registry Data: The Role of Dataset Uniformity

Background: Despite widespread clinical use, the long-term performance of breast implants remains debated. Current evidence is limited by small sample sizes and inconsistent methodologies. National breast device registries provide valuable real-world data, yet their impact is constrained by heterogeneity in variable definitions, data structures, and analytical approaches. The International Collaboration of Breast Registry Activities (ICOBRA) initiative established a harmonized dataset utilized by several countries. Objectives: Evaluate the implementation of the dataset of the ICOBRA across national registries, identify inconsistencies in data definitions and structures, and develop an updated international dataset supporting standardized, federated analyses. Methods: Datasets from 5 national breast implant registries utilizing the harmonized dataset were systematically reviewed. Variations in data points and definitions were identified and discussed through a series of in-person and online consensus meetings. Structured voting was used to finalize revisions and establish the updated international core dataset. Results: Key discrepancies were identified in the classification of surgical indications, inclusion of implant types, and variable definitions across registries. As a result, more than half of the original core variables required revision, reclassification, or removal to enable multinational analyses. A federated analysis model was proposed to accommodate privacy regulations and registry diversity while supporting standardized, risk-adjusted analyses. Conclusions: The updated international breast implant registry dataset represents a crucial step toward integrated global surveillance. Together with standardized statistical methods within a federated data model, it enables robust pooled analyses without requiring uniform registry structures. Countries are encouraged to adopt the revised dataset and contribute to a collaborative framework that enhances patient safety through structured, large-scale data collection and analysis. Level of Evidence 5 Therapeutic: For image description, please refer to the figure legend and surrounding text.