To the Editor While the European Prospective Investigation into Cancer and Nutrition database that Mullee and colleagues1 used to assess the association between soft drink consumption and mortality is quite detailed on treatment exposure (in this case, soft drink servings), such detail is lacking for many potentially important explanatory variables. In nonrandomized (real-world) data, treatment selection can be biased by unobservable confounders or inadequately measured explanatory variables, including in this case: drug use additional to alcohol, detailed exercise and physical activity tracking, income, wealth, education, race/ethnicity, mental health, comorbidities, family and friends, job stress, sleep, major life events, etc. If the association between soft drinks and mortality is not causal, but due to unobserved lifestyle or other factors, then intervening on soft drink consumption directly (eg, through soda taxes or serving size/quantity reductions) will not get at the root cause of the problem.
Identify all potential conflicts of interest that might be relevant to your comment.
Conflicts of interest comprise financial interests, activities, and relationships within the past 3 years including but not limited to employment, affiliation, grants or funding, consultancies, honoraria or payment, speaker's bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued.
Err on the side of full disclosure.
If you have no conflicts of interest, check "No potential conflicts of interest" in the box below. The information will be posted with your response.
Not all submitted comments are published. Please see our commenting policy for details.
Hay JW, Zawadzki NK, Zawadzki R. Hypertension and Unlikely Causality in the Association Between Soft Drink Consumption and Mortality. JAMA Intern Med. 2020;180(2):335–336. doi:10.1001/jamainternmed.2019.6105
Customize your JAMA Network experience by selecting one or more topics from the list below.
Create a personal account or sign in to: