LAUSR

The study by Dutra and Glantz examined cigarette and electronic cigarette (e-cigarette) trends among US middle and high school students via an interrupted time-series analysis of the National Youth Tobacco Survey (NYTS). The authors concluded that the rate of decline in smoking prevalence did not change after the introduction of e-cigarettes into the US market. We vehemently disagree with their choice to test change in slope at 2009 and note additional problems with their methodology and subsequent interpretations. An interrupted time-series study design, “requires a clear differentiation of the preintervention period and the postintervention period…. This does not necessarily require the intervention to be … E-mail: michelle.manderski{at}rutgers.edu