Background Violence-related injury has been an important harmful consequence of drinking in the Latin American and Caribbean (LAC) region, but the risk at which drinking places the individual for violence-related injury or the burden this places on the population is unknown.

Methods A probability sample of 969 emergency room (ER) patients reporting a violence-related injury and arriving within six hours was analysed from 12 ERs in 9 countries in the LAC region. Dose-response relative risk (RR) of violence-related injury based on volume of consumption prior to the event is examined using pair-matched case-crossover fractional polynomial analysis of mean volume and alcohol attributable fraction (AAF) calculated from the RR and prevalence of drinking prior to injury in each volume category.

Results A dose-response relationship was observed with a six-fold increase in risk (RR = 5.88) for less than two drinks prior to injury, increasing to a nine-fold increase (RR = 9.06) for those reporting more than 30 drinks. Risk was similar for males and females up to ten drinks, but higher for females over ten drinks. Risk was higher for those 30 and older compared to those younger at all volume levels, reaching a three-fold increase for 30 or more drinks (RR = 4.78 vs. 14.99). Among all injuries related to violence, 33.56% were attributable to alcohol (population AAF), and among those who reported drinking prior to injury, alcohol was an attributable factor in 87% (exposed AAF). AAF did not vary by age but was nearly three times larger for males (38.66%) than for females (13.52%), although exposed AAF did not differ.

Conclusions A dose-response relationship was found between the amount of alcohol consumed prior to the event and risk of violence-related injury, but risk was not uniform across gender or age. While females were at greater risk of injury than males at higher volume levels, lower prevalence of women drinking at higher levels contributed to overall lower AAF for women.