Abstract:Objective：TTo explore and validate the effectiveness of a “root cause verification-cause‑matched intervention” quality improvement model in a certain grade A tertiary public hospital where the completeness rate of TNM staging documentation in medical records was low（56.0%）. Methods：A self-controlled before-after design was adopted. Baseline review，cause evaluation，Pareto analysis and root cause verification were used to identify fundamental causes and improvement priorities. Targeted interventions included electronic medical record system restructuring，standardized procedures，performance appraisal，and standardization of imaging/pathology reports. Results：After the intervention，the documentation completeness rate increased to 80.2%，a 24.2 percentage point rise from baseline（56.0%，χ2=134.79，P < 0.001）. The information technology transformation enabled automatic data capture，and attribution analysis indicated that informatization contributed approximately 60% to the overall improvement. Conclusion：A root cause‑driven closed‑loop intervention can significantly improve the completeness of TNM staging documentation in medical records. The methodology is replicable and can serve as a reference for improving similar process quality indicators.Objective：TTo explore and validate the effectiveness of a “root cause verification-cause‑matched intervention” quality improvement model in a certain grade A tertiary public hospital where the completeness rate of TNM staging documentation in medical records was low（56.0%）. Methods：A self-controlled before-after design was adopted. Baseline review，cause evaluation，Pareto analysis and root cause verification were used to identify fundamental causes and improvement priorities. Targeted interventions included electronic medical record system restructuring，standardized procedures，performance appraisal，and standardization of imaging/pathology reports. Results：After the intervention，the documentation completeness rate increased to 80.2%，a 24.2 percentage point rise from baseline（56.0%，χ2=134.79，P < 0.001）. The information technology transformation enabled automatic data capture，and attribution analysis indicated that informatization contributed approximately 60% to the overall improvement. Conclusion：A root cause‑driven closed‑loop intervention can significantly improve the completeness of TNM staging documentation in medical records. The methodology is replicable and can serve as a reference for improving similar process quality indicators.