January 20, 2017 From Julian Santaella, lead author of the paper “US Traffic Fatalities 1985-2014 and their Relationship to Medical Marijuana Laws,” responding to our inquiry about IOM 2.0 possibly contradicting his team’s findings:
“I think the sentence ‘there’s a link between marijuana use and increased risk of car crashes’ does not contradict our findings. As you remember, we only answered the question ‘Are medical marijuana laws associated with changes in fatal traffic fatalities?’ And we found that there were reductions as these laws were implemented. We speculate that this could be due to a lower number of drivers driving under the influence of alcohol, because of substitution. However, what the IOM reports indicate is that marijuana use may increase the risk of crashes; if you compare marijuana use vs. alcohol use in an experiment, is likely that the finding would be marijuana use is safer; however, if you compare marijuana use vs. no use of any substance, marijuana use the finding is likely to be that marijuana use increases the risk having an accident while driving.”
Santaella added, regarding the Cult of RCTs:
“I think really good evidence from what can be learned from cohort studies that would be difficult to get with RCTs is what was found with the Framingham cohort study or the Nurses Cohort study, both providing enormous light on the risk associated with smoking and trans fat diets, something that could have never been done in an RCT because of ethical reasons and limitations of the design (controlled situations so different from the real world where multiple interactions are occurring simultaneously).”
