Are cause of death data for Shanghai fit for purpose? A retrospective study of medical records

Objectives To assess the quality of cause of death reporting in Shanghai for both hospital and home deaths. Design and setting Medical records review (MRR) to independently establish a reference data set against which to compare original and adjusted diagnoses from a sample of three tertiary hospitals, one secondary level hospital and nine community health centres in Shanghai. Participants 1757 medical records (61% males, 39% females) of deaths that occurred in these sample sites in 2017 were reviewed using established diagnostic standards. Interventions None. Primary outcome Original underlying cause of death (UCOD) from medical facilities. Secondary outcome Routine UCOD assigned from the Shanghai Civil Registration and Vital Statistics (CRVS) system and MRR UCODs from MRR. Results The original UCODs as assigned by doctors in the study facilities were of relatively low quality, reduced to 31% of deaths assigned to garbage codes, reduced to 2.3% following data quality and follow back procedures routinely applied by the Shanghai CRVS system. The original UCOD had lower chance-corrected concordance and cause-specific mortality fraction accuracy of 0.57 (0.44, 0.70) and 0.66, respectively, compared with 0.75 (0.66, 0.85) and 0.96, respectively, after routine data checking procedures had been applied. Conclusions Training in correct death certification for clinical doctors, especially tertiary hospital doctors, is essential to improve UCOD quality in Shanghai. A routine quality control system should be established to actively track diagnostic performance and provide feedback to individual doctors or facilities as needed.