Measurement properties of a nicotine dependence scale for adolescents.

This paper reports on the measurement properties of a scale intended to measure nicotine dependence in adolescents using data from the American Legacy Longitudinal Tobacco Use Reduction Study. The Nicotine Dependence Scale for Adolescents (NDSA) is a simple linear sum of items associated with behaviors to avoid withdrawal and items associated with experiences of craving. An exploratory factor analysis indicated that the items formed a single scale. The reliability of the scale was assessed by estimating Cronbach's alpha for the scale items. The estimated alpha reliability was.81. The scale's validity was assessed by estimating the correlation between the scale and measures of smoking and quitting behaviors. As hypothesized, the scale was positively correlated with lifetime number of cigarettes smoked (r=.44, p<.001), days smoked in the past 30 days (r=.66, p<.001), cigarettes smoked per day on days smoked (r=.61, p<.001), and number of quit attempts (r=.10, p<.001) and negatively correlated with the length of the quit attempt (r=-.22, p<.001). We also examined the measurement properties of the NDSA separately for middle and high school students and by gender and race or ethnicity. We found no meaningful differences in the measurement properties of the NDSA across these groups. The six-item self-report NDSA had good measurement properties in our sample.