title: [Trends of tobacco use among new students at the Autonomous National University of Mexico, from 1989 to 1998].
abstract: OBJECTIVE
  The purpose of this study was to describe the tobacco smoking patterns in students in the Universidad Nacional Autonoma de Mexico system, (Mexico's National Autonomous University, UNAM), between 1989 and 1998.
  
  
  METHODS
  This is a time-series, cohort study conducted in the year 2000. The overall prevalence of smoking, age- and sex-specific prevalence rates, and the prevalence of subjects smoking 11 or more cigarettes daily, were estimated for 103 582 new students aged 14 to 25 years. The same subjects were contacted for a second time, to estimate the cumulative incidence of smoking during the high school period. Associations were tested using a chi-squared test for trends, and prevalence odds ratios were obtained using a logistic regression model.
  
  
  RESULTS
  The overall prevalence of smoking increased during the study period, mainly after 1993 among younger and female subjects. A higher smoking incidence was found among students of higher economic level. During the high school years, the incidence of smoking initiation was 12% for females and 19% for males. The probability of smoking increased with older age, male gender, and at the final years of the study period.
  
  
  CONCLUSIONS
  In the last decade, evident changes in young students' smoking patterns have occurred. Antitobacco campaigns targeting young people should be implemented.
authors.affiliation: Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Avenida Universidad 655, colonia Santa María Ahuacatitlán, 62508 Cuernavaca, Morelos, México. rayvs@correo.insp.mx
authors.forename: Raydel
authors.initials: R
authors.lastname: Valdés-Salgado
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Micher
authors.forename: Luis
authors.initials: L
authors.lastname: Hernández
authors.forename: Melania
authors.initials: M
authors.lastname: Hernández
authors.forename: Mauricio
authors.initials: M
authors.lastname: Hernández-Avila
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008800:Mexico; D015995:Prevalence; D012907:Smoking / Q000453:epidemiology*; D014495:Universities
vernacular_title: Tendencias del consumo de tabaco entre alumnos de nuevo ingreso a la Universidad Nacional Autónoma de México, 1989 a 1998.