Abstract: Objective Improving the disparities in quality management of blood banks, achieving homogeneous and high-quality collaborative development of the Yangtze River Delta blood station quality system through management mechanism innovation, and providing references for industry advancement. Methods Since 2021, the "Four Unities" joint internal audit model, which includes "Unified training", "Unified review standards", "Unified audit methods" and "Unified result judgment", has been implemented. This model now covers 4 blood centers and 21 central blood banks, and continuous improvement is achieved by categorizing, comparing, and analyzing terms of nonconformity. Results In 2021, 2023 and 2024, 188 terms of nonconformity were identified: 69 at blood centers and 119 at central blood banks. According to "Quality Management Standards for Blood Banks", these non-conformities mainly involve "Safety and Hygiene" (29 items, 15.43%), "Equipment"(23 items, 12.23%), "Records" (22 items, 11.70%) and "Blood Testing" (22 items, 11.70%). According to the classification and analysis of unqualified reasons, there were 23 items of systematic nonconformity (12.23%), 48 items of implementation nonconformity (25.53%) and 117 items of effectiveness nonconformity (62.23%), which caused by the non-conformity between the operating procedures and the quality manual, the failure to implement the requirements and the existence of differences or incorrect records in the operation. Conclusion The implementation of joint internal audits for blood banks in the Yangtze River Delta region through the "Four Unifications" model in quality homogenization provides practical examples and reference models for improving cross-regional blood quality management systems and exploring collaborative approaches for public health management across regions.

Key words: Blood banks, Joint internal audit, Homogenization, The Yangtze River Delta region