title: Replicating cluster subtypes for the prevention of adolescent smoking and alcohol use.
abstract: BACKGROUND
  Substance abuse interventions tailored to the individual level have produced effective outcomes for a wide variety of behaviors. One approach to enhancing tailoring involves using cluster analysis to identify prevention subtypes that represent different attitudes about substance use. This study applied this approach to better understand tailored interventions for smoking and alcohol prevention.
  
  
  METHODS
  Analyses were performed on a sample of sixth graders from 20 New England middle schools involved in a 36-month tailored intervention study. Most adolescents reported being in the Acquisition Precontemplation (aPC) stage at baseline: not smoking or not drinking and not planning to start in the next six months. For smoking (N=4059) and alcohol (N=3973), each sample was randomly split into five subsamples. Cluster analysis was performed within each subsample based on three variables: Pros and Cons (from Decisional Balance Scales), and Situational Temptations.
  
  
  RESULTS
  Across all subsamples for both smoking and alcohol, the following four clusters were identified: (1) Most Protected (MP; low Pros, high Cons, low Temptations); (2) Ambivalent (AM; high Pros, average Cons and Temptations); (3) Risk Denial (RD; average Pros, low Cons, average Temptations); and (4) High Risk (HR; high Pros, low Cons, and very high Temptations).
  
  
  CONCLUSIONS
  Finding the same four clusters within aPC for both smoking and alcohol, replicating the results across the five subsamples, and demonstrating hypothesized relations among the clusters with additional external validity analyses provide strong evidence of the robustness of these results. These clusters demonstrate evidence of validity and can provide a basis for tailoring interventions.
authors.affiliation: Department of Psychiatry, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA.
authors.forename: Steven F
authors.initials: SF
authors.lastname: Babbin
authors.affiliation: Cancer Prevention Research Center, University of Rhode Island, Kingston, RI, USA. Electronic address: velicer@uri.edu.
authors.forename: Wayne F
authors.initials: WF
authors.lastname: Velicer
authors.affiliation: Cancer Prevention Research Center, University of Rhode Island, Kingston, RI, USA.
authors.forename: Andrea L
authors.initials: AL
authors.lastname: Paiva
authors.affiliation: Cancer Prevention Research Center, University of Rhode Island, Kingston, RI, USA.
authors.forename: Leslie Ann D
authors.initials: LA
authors.lastname: Brick
authors.affiliation: Cancer Prevention Research Center, University of Rhode Island, Kingston, RI, USA.
authors.forename: Colleen A
authors.initials: CA
authors.lastname: Redding
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000523:psychology*; D000428:Alcohol Drinking / Q000517:prevention & control / Q000523:psychology*; D001294:Attitude to Health; D002648:Child; D016000:Cluster Analysis; D005260:Female; D006801:Humans; D008297:Male; D009042:Motivation; D015203:Reproducibility of Results; D012907:Smoking / Q000523:psychology*; D000074606:Smoking Prevention
keywords: Alcohol acquisition; Cluster analysis; Prevention; Smoking acquisition