Under-recording of ethanol intoxication and poisoning in cause-of-death data: causes and consequences

In the present study we examined how consistently and completely the role of acute alcohol (ethanol) intake as a cause of death is reported on death certificates, how complete and specific the statistical recording of cause-of-death data on acute alcohol-induced deaths is, and how the information ultimately appears in the national mortality statistics. Data on all alcohol-positive deaths with blood alcohol concentration of ≥ 0.5‰ (g/kg) in Finland in 2005 (N = 2348) were reviewed. Overall, a concentration-dependent association was found between forensic-toxicologically determined blood alcohol concentrations and acute alcohol-specific cause-of-death diagnoses. Based on a medico-legal re-evaluation of death certificates, acute alcohol-specific causes were found to be underreported nationally at a rate of 8%. For accidental alcohol poisonings alone, the figure was about 1%. This underreporting was not corrected during recording of the cause-of-death data, though individual corrections and changes were observed. Especially, recording of multiple causes suffers from this underreporting of acute alcohol-specific causes. ICD-10 seems to do well in fulfilling the demands for a specific classification of uncomplicated alcohol poisoning. In combined alcohol-drug poisonings, however, ICD-10 shows a bias towards drugs over alcohol, even when alcohol has been specified and reported as the most toxic component by the medico-legal pathologist. Since the national statistics is based on the underlying causes, this state of affairs is likely to result in the underestimation of the role of acute alcohol intake as a cause of death. This observation of underreporting of acute alcohol-specific causes on death certificates should result in a harmonisation of education and principles and practices used in death certification. To increase the coverage and specificity of mortality statistics, based on the underlying causes of death, the coding of all components of alcohol-drug combinations and their classification according to the most important intoxicant or combination of intoxicants is recommended.