Predicting complications in immediate microvascular breast reconstruction: Validity of the breast reconstruction assessment (BRA) surgical risk calculator

Summary Background The Breast Reconstruction Assessment (BRA)-score is a disease-specific risk calculator that estimates the likelihood of postoperative complications in an individual patient. The tool has not been previously externally validated in microvascular breast reconstruction. The purpose of this study was to evaluate the efficacy of the calculator in patients who underwent microvascular reconstruction at a single specialist institution. Methods Data from 415 patients who had immediate microvascular breast reconstruction were entered into the calculator. The predicted and observed rates of surgical complications, medical complications, reoperation, and total or partial flap failure were compared. The accuracy of the calculator was assessed using statistical measures of calibration and discrimination. Results The calculator accurately predicted the proportion of patients who would experience surgical complications and reoperations but overestimated the rates of medical complications and flap failures. The C-statistics were low for all four prediction models (0.49–0.59), suggesting weak discriminatory power, and the Brier scores were relatively high (0.09–0.44), indicating poor correlation between predicted and actual probability of complications. Conclusion These results suggest that the BRA score cannot accurately identify patients at risk for complications following immediate microvascular breast reconstruction at our institution.