State Variation in Underreporting of Alcohol Involvement on Death Certificates: Motor Vehicle Traffic Crash Fatalities as an Example

Objective: We used motor vehicle traffic (MVT) crash fatalities as an example to examine the extent of underreporting of alcohol involvement on death certificates and state variations. Method: We compared MVT-related death certificates identified from national mortality data (Multiple Cause of Death [MCoD] data) with deaths in national traffic census data from the Fatality Analysis Reporting System (FAIRS). Because MCoD data were not individually linked to FAIRS data, the comparisons were at the aggregate level. Reporting ratio of alcohol involvement on death certificates was thus computed as the prevalence of any mention of alcohol-related conditions among MVT deaths in MCoD, divided by the prevalence of decedents with blood alcohol concentration (BAC) test results (not imputed) of .08% or greater in FAIRS. Through bivariate analysis and multiple regression, we explored state characteristics correlated with state reporting ratios. Results: Both MCoD and FAIRS identified about 450,000 MVT deaths in 1999-2009. Reporting ratio was only 0.16 for all traffic deaths and 0.18 for driver deaths nationally, reflecting that death certificates captured only a small percentage of MVT deaths involving BAC of .08% or more. Reporting ratio did not improve over time, even though FAIRS indicated that the prevalence of BAC of at least .08% in MVT deaths increased from 19.9% in 1999 to 24.2% in 2009. State reporting ratios varied widely, from 0.02 (Nevada and New Jersey) to 0.81 (Delaware). Conclusions: The comparison of MCoD with FAIRS revealed a large discrepancy in reporting alcohol involvement in MVT deaths and considerable state variation in the magnitude of underreporting. We suspect similar underreporting and state variations in alcohol involvement in other types of injury deaths.