title: Smoking initiation among Israeli adolescents: a 24-year time-to-event analysis.
abstract: BACKGROUND
  Preventing smoking initiation will protect future generations from smoking-attributable death and disease. This study examines the correlates and patterns of initiation among Israeli youth using time-to-event analysis and other methods.
  
  
  METHODS
  Twenty-four consecutive representative samples (1986-2009) of new military recruits (N=50,254) were analyzed. Cox regression and Kaplan-Meier analysis were used to identify factors associated with smoking initiation, and logistic regression was used to identify factors associated with smoking status.
  
  
  RESULTS
  The most hazardous age for smoking initiation was seventeen, subsequent to the mean age of smoking initiation (males: 15.7, females: 16.0). Age of initiation and age of greatest hazard for initiation declined among recruits between the years 1986 and 2009. Earlier smoking initiation among boys and girls was significantly associated with low education levels (<12years) (males: HR=2.98, CI: [2.79, 3.18]; females: HR=3.35, CI: [2.96, 3.80]), low paternal education levels, Russian birthplace, and religion. Earlier initiation in boys was associated with high fitness levels and low/medium socio-economic status. Earlier initiation in girls was associated with being Western-born and ever-use of contraception.
  
  
  CONCLUSIONS
  Smoking initiation among Israeli youth recruited to the armed forces is associated with individual and family characteristics, particularly low education levels. Time-to-event analysis complements traditional means of understanding smoking initiation by identifying ages at which initiation hazard is high.
authors.affiliation: Dept. of Health Promotion, School of Public Health, Sackler Faculty of Medicine, Tel Aviv University, Israel. Electronic address: Rosenl@post.tau.ac.il.
authors.forename: L
authors.initials: L
authors.lastname: Rosen
authors.affiliation: Preventive Medicine Branch, Medical Corps, Israel Defense Force, Israel. Electronic address: vladiro81@gmail.com.
authors.forename: V
authors.initials: V
authors.lastname: Rozhavski
authors.affiliation: Preventive Medicine Branch, Medical Corps, Israel Defense Force, Israel; Hebrew University-Hadassah Braun School of Public Health and Community Medicine, Ein Kerem, Jerusalem, Israel. Electronic address: hlevine@hadassah.org.il.
authors.forename: H
authors.initials: H
authors.lastname: Levine
authors.affiliation: Preventive Medicine Branch, Medical Corps, Israel Defense Force, Israel. Electronic address: tamars@actcom.co.il.
authors.forename: T
authors.initials: T
authors.lastname: Sela
authors.affiliation: Dept. of Health Promotion, School of Public Health, Sackler Faculty of Medicine, Tel Aviv University, Israel; Preventive Medicine Branch, Medical Corps, Israel Defense Force, Israel. Electronic address: yaelbz1@gmail.com.
authors.forename: Y
authors.initials: Y
authors.lastname: Bar-Ze'ev
authors.affiliation: Preventive Medicine Branch, Medical Corps, Israel Defense Force, Israel; The Health Systems Management Program, Department of Management, Bar Ilan University, Israel. Electronic address: vered.molina@gmail.com.
authors.forename: V
authors.initials: V
authors.lastname: Molina-Hazan
authors.affiliation: Preventive Medicine Branch, Medical Corps, Israel Defense Force, Israel; School of Public Health, University of Haifa, Israel. Electronic address: zarkas@netvision.net.il.
authors.forename: S
authors.initials: S
authors.lastname: Zarka
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000208:ethnology; D017668:Age of Onset; D004522:Educational Status; D005260:Female; D006801:Humans; D007557:Israel / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D008297:Male; D008889:Military Personnel / Q000706:statistics & numerical data*; D015995:Prevalence; D016016:Proportional Hazards Models; D012307:Risk Factors; D017678:Sex Distribution; D012907:Smoking / Q000453:epidemiology* / Q000208:ethnology; D000074606:Smoking Prevention
keywords: Cox proportional hazards model; Hazard; Smoking initiation; Survival analysis; Time-to-event analysis; Tobacco control; Youth smoking prevention