In recent years, a bunch of studies have reported correlations between nicotine vaping and various smoking-related diseases, seemingly undermining the case for e-cigarettes as a harm-reducing alternative to combusted tobacco. But as a new analysis in the journal Internal and Emergency Medicine notes, those studies paid no attention to the question of whether the diseases were diagnosed before or after the subjects began vaping—a glaring omission when you are trying to figure out whether the associations indicate cause-and-effect relationships.
Sometimes information on the timing of diagnoses was not included in the survey data on which researchers relied. But the Population Assessment of Tobacco and Health (PATH) Survey, which was the basis for some of the studies, does include such information, which the authors conspicuously ignored. In the Internal and Emergency Medicine article, University of Louisville researchers Brad Rodu and Nantaporn Plurphanswat consider those overlooked data and find that the diseases reported by subjects generally predated their first use of vaping products, making a causal interpretation logically impossible.
