Estimating alcohol-attributable fractions for injuries based on data from emergency department and observational studies: a comparison of two methods

Abstract

Aim: To compare the injury alcohol-attributable fractions (AAFs) estimated using emergency department (ED) data to AAFs estimated by combining population alcohol consumption data with corresponding relative risks (RRs).

Design: Comparative risk assessment.

Setting and participants: ED studies in 27 countries (n = 24 971).

Measurements: AAFs were estimated by means of an acute method using data on injury cases from 36 ED studies combined with odds ratios obtained from ED case-cross-over studies. Corresponding AAFs for injuries were estimated by combining population-level data on alcohol consumption obtained from the Global Information System on Alcohol and Health, with corresponding RRs obtained from a previous meta-analysis.

Findings: ED-based injury AAF estimates ranged from 5% (Canada 2002 and the Czech Republic) to 40% (South Africa), with a mean AAF among all studies of 15.4% (18.9% for males and 8.4% for females). Population-based injury AAF estimates ranged from 21% (India) to 51% (Spain and the Czech Republic), with a mean AAF among all country-years of 36.8% (42.5% for males and 22.5% for females). The Pearson correlation coefficient for the two types of injury AAF estimates was 0.09 for the total, 0.06 for males and 0.32 for females.

Conclusions: Two methods of estimating the injury alcohol-attributable fractions-emergency department data versus population method-produce widely differing results. Across 36 country-years, the mean AAF using the population method was 36.8%, more than twice as large as emergency department data-based acute estimates, which average 15.4%.

Keywords: Alcohol-attributable fraction; emergency department; injury; mortality and morbidity; population alcohol consumption; relative risk.