Waterpipe a gateway to cigarette smoking initiation among adolescents in Irbid, Jordan: a longitudinal study

Abstract

Setting: According to anecdotal evidence, waterpipe smoking may lead to the initiation of cigarette smoking among young people. This hypothesis is yet to be examined using an appropriate study design and a theoretical model for behavioral change.

Objective: To compare the risk of cigarette smoking initiation among waterpipe-only smokers and never smokers in a school-based sample of adolescents from Irbid, Jordan.

Methods: A total of 1454 cigarette-naïve participants were drawn from a longitudinal study on smoking behavior conducted in Irbid among 1781 seventh graders who were enrolled at baseline (2008) and completed the study questionnaire on smoking behavior annually until 2011. Grouped time-survival analysis was used to compare the risk of subsequent initiation of cigarette smoking between waterpipe smokers (n = 298) and never smokers (n = 1156) using adjusted hazard ratios (aHRs) and 95% confidence intervals (95%CI).

Results: Risk of initiation of cigarette smoking among waterpipe smokers was significantly higher than among never smokers after adjusting for potential confounders (aHR 1.67, 95%CI 1.46-1.92). The association between waterpipe and cigarette smoking initiation was dose-dependent. The risk of initiating cigarette smoking increased with increase in the frequency of waterpipe smoking (P for linear trend < 0.001).

Conclusions: Waterpipe smoking led to the initiation of cigarette smoking among this cohort of Jordanian adolescents; the effect was dose-dependent.

Figure 1

Adjusted probabilities* of initiating cigarette smoking for waterpipe-only smokers compared with never smokers in a school-based sample of adolescents in Irbid, Jordan, 2008–2011 (n = 1454). Note: probabilities were obtained from the adjusted grouped-time survival analysis. Modeling included sex; age; pocket money; educational level of parents; whether parents, siblings, friends, teacher smoked cigarettes; relation with parents, siblings, teachers and classmates; intention to smoke; refusal of self-efficacy; beliefs (cigarette smoker has more friends, cigarette smoking is more attractive, cigarette smoking reduces weight, cigarette smoking harms health, easy to quit cigarette after smoking a year); intention to smoke next year; and whether the student has seen advertisements promoting or warning against cigarette smoking or actor smoking in the media, and warning label on cigarette packs.* Based on dose-response linear trend analysis.

Figure 2

The 12-month average predicted probabilities of initiating cigarette smoking as a function of frequency of waterpipe smoking in the previous year among a school-based sample of adolescents in Irbid, Jordan, 2008–2011 (n = 1454). Note: adjusted for sex; age; pocket money; educational level of parents; whether parents, siblings, friends, teacher smoked cigarettes; relation with parents, siblings, teachers and classmates; intention to smoke; refusal of self-efficacy; beliefs (cigarette smoker has more friends, cigarette smoking is more attractive, cigarette smoking reduces weight, cigarette smoking harms health, easy to quit cigarette after smoking for a year; intention to smoke next year; and whether the student has seen advertisements promoting or warning against cigarette smoking or actor smoking in the media, and warning label on cigarette packs.* Based on dose-response linear trend analysis.