The survey questionnaire was developed in accordance with international guidelines (World Health Organization, 1998), as well as Rapamycin order instruments that were used and tested in Arabic (Maziak, Eissenberg, & Ward, 2005; Tamim et al., 2007). The questionnaire was comprised of four modules: sociodemographic module (including, age, gender, number of persons in the household, number of rooms of the house, father and mother��s education level, and daily allowance), cigarette smoking module, water-pipe smoking module, and the fourth module asking about tobacco ads and smoking warnings, family and school environment, peer influences, and students�� attitude to quitting smoking. Special attention was devoted to the clarity of items to allow for similar cognitive processing by the respondents.

For example, concept- or linguistic-laden questions were avoided (e.g., to assess peer pressure, we asked about ��smoking among close friends�� rather than ��peer pressure��). The questionnaire was piloted in 86 boys and 67 girls from four schools in Irbid and further modified to address issues revealed during the piloting. Procedures and Definitions The questionnaire was group-administered by one of the study personnel. In each classroom, a study staffer explained the purpose of the study to students, showed them how to answer the questionnaire, and answered their questions. To improve the validity of students�� responses, no teachers or other school personnel were allowed in the classroom during data collection. The following definitions of smoking status were used: ��Ever smoking�� is ever smoking a cigarette/water pipe, even a puff or two.

��Current smoking�� is reported tobacco use (cigarette, water pipe) in the past 30 days. ��Regular smoking�� is smoking at least once a week in the past 30 days. ��Never smoking�� is reporting never having experimented with tobacco. The intention to smoke is assessed from responses to the question: ��Do you think that you may start to smoke cigarettes [waterpipe] next year?�� To obtain more stable estimations, ��yes�� and ��maybe�� responses are grouped together because of the small numbers in each category. The positive predictive value (PPV) of this question is calculated by dividing number who answered ��yes/maybe�� to this question and became ever-smokers after 2 years by the total number who answered ��yes/maybe�� on the question: Parental consent and students�� assent were obtained from all participants.

The study was reviewed and approved by the Jordan University for Science and Technology and the University of Memphis institutional review boards. Statistical Analysis Data were summarized as number and percent of total. Chi-square test was used to compare Dacomitinib smoking prevalence in boys and girls and between water pipe and cigarettes. McNemar test was used to compare smoking status over time (between baseline and 2-year follow-up).