The Syrian Center for Tobacco Studies-13 (SCTS-13): Psychometric evaluation of a waterpipe-specific nicotine dependence instrument

Abstract

Background: Waterpipe tobacco smoking (WTS) has surged globally among young people and causes nicotine dependence (ND). No existing ND instruments are sensitive to waterpipe-specific features of ND and early stages of use.

Methods: We conducted a psychometric scale evaluation among 192 current waterpipe smokers, initially averaging 15 years of age, recruited from schools in Beirut, Lebanon, and assessed 4 times, 6 months apart. Twenty eight self-report items tapping multiple features of ND were submitted to exploratory and confirmatory factor analyses (EFA and CFA) to reduce items and verify factor structure. Convergent validity was assessed with the Lebanese Waterpipe Dependence Scale and the Hooked on Nicotine Checklist, and discriminant validity with the Depressive Symptom Scale and Adolescent Life Events Stress Scale. Concurrent and predictive validity measures included smoking status and intensity (amount, frequency, session duration, and change in frequency), quitting interest and success, perceived addiction, and smoking alone.

Results: The EFA yielded a single factor, 13 item solution (named the Syrian Center for Tobacco Studies [SCTS]-13) that explained 91% of variance in responses, was internally consistent (Cronbach's alpha and McDonald's omega = 0.87), and captured several positive reinforcement, negative reinforcement, and social/sensory-related features of ND. The CFA indicated good model fit. The SCTS-13 showed acceptable convergent and discriminant validity. Higher SCTS-13 scores predicted current waterpipe and dual (waterpipe and cigarette) smoking, greater intensity of use, less interest in quitting, shorter duration of abstinence, greater perceived addiction, and smoking alone (vs. socially).

Conclusion: The SCTS-13 is a promising brief, waterpipe-specific ND instrument.

Keywords: Nicotine dependence; Psychometrics; Tobacco; Waterpipe.