Empty glasses and broken bones : epidemiological studies on alcohol and injuries treated at an emergency department in Switzerland

Abstract

Background: Injury-related deaths and Disability-Adjusted Life Year (DALY) represent an important share of the burden of disease worldwide. Acute prior-to-injury alcohol consumption is a known risk factor for injuries. Traffic- and violence-related injuries have received lots of attention in this regard, and intentional injuries consistently show higher figures for acute consumption compared to other non-intentional injuries. In addition, it was recently suggested that usual drinking patterns could play a role in the alcohol and injury phenomenon.

Objectives:The thesis aims to increase knowledge on alcohol use as an injury determinant and gives special attention to alcohol consumption as a human factor involved in the pre-event and event phases of injuries. The association of alcohol consumption with various injury factors is first examined, followed by the estimation of alcohol-related risks and attributable fractions. The validity of the alcohol consumption measurements used within the thesis is finally investigated in order to validate the presented findings.

Material:The thesis is built around five articles (Articles I to V) analyzing data collected within two different Emergency Department (ED) studies conducted at the Lausanne University Hospital in Switzerland (data collection: 2003-2004 and 2005-2006).

Results: A considerable proportion of ED treated injuries occurred after the patient had been drinking (about 25% in the preceding 6 hours). Acute consumption was found to be associated with some typical injury circumstances (Article I) and showed marked variations across time (Article II). Specific usual drinking patterns showed similarly associations with certain injury circumstances (Article I). When deriving risk estimates for different mechanisms, natures of injury, and body regions, low levels of acute alcohol consumption showed to be a risk factor for almost all considered outcomes (Articles III & IV). Persistent dose-response effects between alcohol levels and risk estimates were observed. Whereas risk associations did not vary meaningfully by type of injury (natures and body regions; Article IV), they did vary when estimated for different injury mechanisms (interpersonal violence demarked consistently from other mechanisms; Article III). Also, it was estimated that 33.1% of interpersonal violence-related injuries, 19.7% of falls, 15.2% of injuries due to exposure to forces and other events, and 15.4% of transportation-related injuries could be attributed to alcohol consumption in the preceding 24-hour period (Article III). In addition, most of the total alcohol-attributable fractions for the three non-intentional mechanisms were associated with low levels of acute consumption. Finally, corroboration between self-reported and biological measures of acute alcohol consumption is observed in the study population (Article V).

Discussion: The results described in the thesis highlight the strong implication of alcohol consumption in injuries treated in emergency departments in Switzerland. By suggesting associations of acute and usual drinking with specific and/or unspecific injury circumstances or characteristics, the findings present an original picture of the alcohol and injury phenomenon. The estimation of alcohol-related injury risks showed that individuals are at higher risk for injury from the first drink and that this (relative) risk increases with increasing levels of consumption. The derivation of alcohol-attributable fractions underlined that many injuries would have been avoided if patients had abstained from drinking in the event .

Conclusion: This thesis suggests that future interventions should not only target patients with at-risk drinking profiles. Since episodes of relatively low levels of alcohol consumption were responsible for the major share of alcohol-attributable injuries, these episodes should be targeted. Consequently, population-based approaches could be appropriate means to significantly reduce the alcohol-related injury burden in Switzerland.