Aims
Update and extend analysis of the dose-response relationship of injury and drinking by demographic and injury subgroups and country-level drinking pattern, and examine the validity and efficiency of the fractional polynomial approach to modeling this relationship.
Design
Pair-matched case-crossover analysis of drinking prior to injury, using categorical step-function and fractional polynomial analysis.
Setting
37 emergency departments (EDs) across 18 countries.
Participants
13,119 injured drinkers arriving at the ED within six hours of the event
Measurements
The dose-response relationship was analyzed by gender, age, cause of injury (traffic, violence, fall, other), and country detrimental drinking pattern (DDP).
Findings
Estimated risks were similar between the two analytic methods, with injury risk doubling at one drink (OR = 2.3 – 2.7) and peaking at about 30 drinks. Although risk was similar for males and females up to three drinks (OR = 4.6), it appeared to increase more rapidly for females and was significantly higher starting from 20 drinks (female OR = 28.6; CI (16.8, 48.9); male OR = 12.8; CI (10.1, 16.3)). No significant differences were found across age groups. Risk was significantly higher for violence-related injury than for other causes across the volume range. Risk was also higher at all volumes for DDP-3 compared to DDP-2 countries
Conclusions
An increasing risk relationship was found between alcohol and injury, but risk was not uniform across gender, cause of injury, or country drinking pattern. The fractional polynomial approach was found to be a valid and efficient approach for modeling the alcohol-injury risk relationship.