Argentine ER study finds alcohol and combined alcohol-cannabis use dramatically increase road traffic injury risk | Research

The takeaway

Among 306 injured emergency department patients in Argentina, alcohol increased road traffic injury risk nearly 7-fold, and combined alcohol-cannabis use showed similar risk, with passengers facing the highest risk from alcohol.

Traffic safety researchers, policymakers in Latin America, and public health professionals.

Alcohol: 6.8x risk; alcohol + cannabis: 7.1x risk for road injury

What the researchers found

Alcohol use increased road traffic injury risk 6.78-fold (95% CI 3.75-12.25). Combined alcohol and cannabis use increased risk 7.05-fold (95% CI 1.16-42.73). Passengers had the highest alcohol-related risk (OR 13.83). The combined alcohol-cannabis risk was significant only for those under 30. Cannabis alone was not separately analyzed due to insufficient cases.

Why it matters

These are the first road traffic injury risk estimates for alcohol and cannabis in the Southern Cone of South America, providing data relevant to impaired driving policy in a region where cannabis legalization is advancing.

The numbers in context

N=306; alcohol OR=6.78; combined alcohol+cannabis OR=7.05; women OR=8.87; men OR=6.16; passengers OR=13.83; under 30 with combined use OR=7.05.

How the study worked

Case-crossover study of 306 injured emergency department patients in Mar del Plata, Argentina. Each patient served as their own control, comparing substance use at the time of injury to their typical use patterns.

What this study cannot tell us

Relatively small sample. Wide confidence intervals for combined alcohol-cannabis risk. Cannabis alone not separately analyzed. Self-report of substance use. Single hospital in one city.

How to read the evidence

Case-crossover design reduces confounding but small sample and wide confidence intervals limit precision.

When this study was published

Published in 2022.

The bigger picture

The finding that combined alcohol-cannabis risk was significant only for those under 30 highlights young adults as a particularly vulnerable group for polysubstance-impaired driving.

Questions still open

What is the independent risk of cannabis alone for road traffic injury in this population? Would the combined risk be different in a larger sample? How should impaired driving laws address polysubstance use?

Common questions

How much does alcohol increase road accident risk?

In this study, alcohol use increased road traffic injury risk nearly 7 times. Passengers in vehicles with alcohol-using drivers had an even higher risk (nearly 14 times).

Is combining alcohol and cannabis more dangerous for driving?

Combined alcohol and cannabis use showed a 7-fold increase in road traffic injury risk, similar to alcohol alone. However, this combined risk was only significant for people under 30.

Read the original research

Road traffic injury risk from alcohol and cannabis use among emergency department patients in Argentina.

Revista panamericana de salud publica = Pan American journal of public health, 46, e116

View on PubMed ↗Publisher’s paper ↗

Citation

Conde, Karina; Peltzer, Raquel Inés; Gimenez, Paula Victoria; Salomón, Tomás; Suarez, Gabriel; Monteiro, Maristela; Cherpitel, Cheryl J; Cremonte, Mariana. (2022). Road traffic injury risk from alcohol and cannabis use among emergency department patients in Argentina.. Revista panamericana de salud publica = Pan American journal of public health, 46, e116. https://doi.org/10.26633/RPSP.2022.116