title: Discontinuous Patterns of Cigarette Smoking From Ages 18 to 50 in the United States: A Repeated-Measures Latent Class Analysis.
abstract: BACKGROUND
  Effective cigarette smoking prevention and intervention programming is enhanced by accurate understanding of developmental smoking pathways across the life span. This study investigated within-person patterns of cigarette smoking from ages 18 to 50 among a US national sample of high school graduates, focusing on identifying ages of particular importance for smoking involvement change.
  
  
  OBJECTIVE
  Using data from approximately 15,000 individuals participating in the longitudinal Monitoring the Future study, trichotomous measures of past 30-day smoking obtained at 11 time points were modeled using repeated-measures latent class analyses. Sex differences in latent class structure and membership were examined.
  
  
  RESULTS
  Twelve latent classes were identified: three characterized by consistent smoking patterns across age (no smoking; smoking < pack per day; smoking pack + per day); three showing uptake to a higher category of smoking across age; four reflecting successful quit behavior by age 50; and two defined by discontinuous shifts between smoking categories. The same latent class structure was found for both males and females, but membership probabilities differed between sexes. Although evidence of increases or decreases in smoking behavior was observed at virtually all ages through 35, 21/22 and 29/30 appeared to be particularly key for smoking category change within class.
  
  
  CONCLUSIONS
  This examination of latent classes of cigarette smoking among a national US longitudinal sample of high school graduates from ages 18 to 50 identified unique patterns and critical ages of susceptibility to change in smoking category within class. Such information may be of particular use in developing effective smoking prevention and intervention programming.
  
  
  CONCLUSIONS
  This study examined cigarette smoking among a national longitudinal US sample of high school graduates from ages 18 to 50 and identified distinct latent classes characterized by patterns of movement between no cigarette use, light-to-moderate smoking, and the conventional definition of heavy smoking at 11 time points via repeated-measures latent class analysis. Membership probabilities for each smoking class were estimated, and critical ages of susceptibility to change in smoking behaviors were identified.
authors.affiliation: Institute for Social Research, University of Michigan, Ann Arbor, MI.
authors.forename: Yvonne M
authors.initials: YM
authors.lastname: Terry-McElrath
authors.affiliation: Institute for Social Research, University of Michigan, Ann Arbor, MI.
authors.forename: Patrick M
authors.initials: PM
authors.lastname: O'Malley
authors.affiliation: Institute for Social Research, University of Michigan, Ann Arbor, MI.
authors.forename: Lloyd D
authors.initials: LD
authors.lastname: Johnston
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000073865:Cigarette Smoking / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D016540:Smoking Cessation / Q000523:psychology*; D014029:Tobacco Use Disorder / Q000453:epidemiology* / Q000517:prevention & control / Q000523:psychology; D014481:United States / Q000453:epidemiology; D055815:Young Adult