The LWDS-10J: reliability and validity of the Lebanon Waterpipe Dependence Scale among university students in Jordan.

INTRODUCTION: While the Lebanon Waterpipe Dependence Scale (LWDS-11) has shown promise in assessing dependence on waterpipe tobacco smoking (WTS) in Lebanon among adult users, it would be valuable to identify WTS addiction earlier and to explore reliability and validity of these items in other populations. METHODS: In 2010-2012, we conducted a multiyear survey of 5,853 students from 4 Jordanian universities. We measured WTS, sociodemographic data, and the LWDS-11 items. We conducted exploratory factor analysis with half of the sample and confirmed the resulting model using confirmatory factor analysis with the other half. We examined construct validity with regression models assessing associations between the modified scale and 5 constructs conceptually expected to be associated with dependence. RESULTS: WTS rates were 35% in the past 30 days and 56% ever. Principal-components analysis of LWDS items in the first half of the sample yielded 10 items representing 3 factors labeled physical dependence, relaxation/pleasure, and social aspects. Cronbach's α was .77 for the total scale and was .75, .70, and .67 for each individual subscale. Confirmatory factor analysis in a structural equation modeling framework confirmed good fit (root mean squared error of approximation = 0.068, and comparative fit index = 0.937). Dependence according to the resulting scale (LWDS-10J) was strongly associated with each of the 5 expected constructs, whether the dependent variable was treated as categorical or continuous. CONCLUSIONS: The LWDS-11 items exhibited a different factor structure in our sample. However, the modified scale (LWDS-10J) showed promising reliability and construct validity in this population.