The researchers argue that the way that earlier studies measured alcohol's impact on health might be flawed. Specifically, they note that the studies are generally observational and usually recruit participants over the age of 50.
The authors argue that this is problematic because it excludes anyone who might have died due to alcohol before the age of 50. As they dryly point out, "Deceased persons cannot be enrolled in cohort studies."
Dr. Naimi first outlined his concerns about this inherent selection bias in a paper published in the journal Addiction in 2017.
According to the authors, almost 40 percent of deaths due to alcohol consumption occur before the age of 50.
This means that the vast majority of research into the potential risks of alcohol do not take these deaths into account and could underestimate the real dangers.
To reinvestigate, the authors dipped into data from the Alcohol-Related Disease Impact Applicationwhich is maintained by the Centers for Disease Control and Prevention (CDC). According to the CDC, this application "provides national and state estimates of alcohol-related health impacts, including deaths and years of potential life lost."