Purpose China has a population of 1.4 billion and an enormous medical expenditure burden, and Chinese traditional culture has a long history. It takes time to recognize and accept the concept of brain death (BD) as death. Promoting brain death determination (BDD) and rationally allocating medical resources have become major national policy issues. To identify the safest and most reliable ancillary tests needed if the clinical examination is incomplete.

Method The technical group of the Brain Injury Evaluation Quality Control Center of the National Health Commission retrieved coma cases registered from 2013 to 2019. According to clinical criteria for Brain Death Determination (BDD), the patients were divided into two groups: a brain-death (BD) group and a non-BD group. The BD group was divided into a complete brain death with no doubt group (BD1 group) and an incomplete brain death with doubt group (BD2 group). Depending on the site of the brain injury, the accuracy of BDD was evaluated using the independent ancillary test or combined ancillary tests. Data from the BQCC/NHC database and yearbook were obtained, and data analysis and status comparison were conducted on six practical activities: organizational system construction, standard and specification formulation, case quality control, professional skills training, scientific research publicity and education, and international communication.

Inclusion Criteria:

• All cases met the clinical criteria for BD, involving deep coma (Glasgow Coma Scale (GCS)=2T), the absence of brainstem reflexes (pupillary light reflex, corneal reflex, oculocephalogyric reflex, oculovestibular reflex, and cough reflex), and spontaneous respiration. Ancillary tests were completed for all patients.

Exclusion Criteria:

• Does not meet BD clinical evaluation criteria. Ancillary tests were not implemented.

Coma cases registered by the National Brain Death Determination Quality Control Demonstration Hospital (BDQCH) in the BQCC/NHC from 2013 to 2019 were retrieved.