Grant: Operating Grant

Alcohol use increases the risk of injury according to the quantity consumed. This relationship varies according to where drinking takes place (e.g. a bar, public place, private home) and type of activity engaged in (e.g. driving, eating a meal). The present study will explore how injury risk changes when a person is also using some kind of stimulant, such as an "energy drink", cocaine or amphetamine-type drugs. Increasingly, risky substance use involves a pattern of combined alcohol and other drug use and there is evidence that this further increases the risk of injury. Canada has regulations to limit the caffeine content of alcoholic beverages. Unfortunately, most combined alcohol and energy drinks consumed in Canada are not pre-mixed and, instead, drinkers combine separate alcoholic and energy drinks. There may be a need for further regulation of energy drink in places where alcohol is sold. We propose the first controlled study of how combined alcohol and energy drink consumption increases injury risk. The team has considerable experience with emergency room studies investigating substance use and other activities immediately before their injury. One member of the team invented the "case-crossover" study design, which has been increasingly used in epidemiological research worldwide. We will apply this method so that individuals presenting to the ER will provide information not only on their substance use and other activities immediately before their injury or acute illness, but also, (i) at the same time the previous week, (ii) the last time they were in the particular setting in which they experienced their injury or illness. We will then estimate how risk of injury increases with increasing doses of alcohol, energy drinks and other illegal stimulants separately and in combination. We will also investigate how these estimates vary by gender, age and context of substance use. The results will be shared with policymakers and other researchers.