Comparing road traffic mortality rates from police-reported data and death registration data in China.

OBJECTIVE To compare death rates from road traffic injuries in China in 2002-2007 when derived from police-reported data versus death registration data. METHODS In China, police-recorded data are obtained from police records by means of a standardized, closed-ended data collection form; these data are published in the China statistical yearbook of communication and transportation. Official death registration data, on the other hand, are obtained from death certificates completed by physicians and are published in the China health statistics yearbook. We searched both sources for data on road traffic deaths in 2002-2007, used the χ(2) test to compare the mortality rates obtained, and performed linear regression to look for statistically significant trends in road traffic mortality over the period. FINDINGS For 2002-2007, the rate of death from road traffic injuries based on death registration data was about twice as high as the rate reported by the police. Linear regression showed a significant decrease of 27% (95% confidence interval, CI: 35-19) in the death rate over the period according to police sources but no significant change according to death registration data. CONCLUSION The widely-cited recent drop in road traffic mortality in China, based on police-reported data, may not reflect a genuine decrease. The quality of the data obtained from police reports, which drives decision-making by the Government of China and international organizations, needs to be investigated, monitored and improved.