title: A match-mismatch test of a stage model of behaviour change in tobacco smoking.
abstract: OBJECTIVE
  An innovation offered by stage models of behaviour change is that of stage-matched interventions. Match-mismatch studies are the primary test of this idea but also the primary test of the validity of stage models. This study aimed at conducting such a test among tobacco smokers using the Social Cognitive Stage Model.
  
  
  METHODS
  A match-mismatch field-experiment was conducted in which smokers and ex-smokers in different stages were assigned randomly to one of three information conditions.
  
  
  METHODS
  Smokers in the pre-contemplation stage, the contemplation stage and the preparation stage, and ex-smokers in the action stage (n = 481), who were recruited through mass media, were assigned randomly to one of three information conditions.
  
  
  METHODS
  In each of the three information conditions, participants received a four- to six-page computer-tailored letter designed to: (1) increase the positive outcome expectations of quitting, (2) decrease the negative outcome expectations of quitting or (3) increase self-efficacy.
  
  
  METHODS
  Forward stage transition was the primary outcome measure, which was assessed 2 months after the participants received the information.
  
  
  RESULTS
  At the 2-month follow-up, the matched interventions were significantly more effective in stimulating forward stage transition (44.7%) than were mismatched interventions (25.8%; odds ratio = 2.78; confidence interval = 1.85-4.35).
  
  
  CONCLUSIONS
  The present study provides experimental support for the benefits of stage-matching and for the validity of the Social Cognitive Stage Model.
authors.affiliation: Leiden University, Leiden, the Netherlands. arie.dijkstra@rug.nl
authors.forename: Arie
authors.initials: A
authors.lastname: Dijkstra
authors.forename: Barbara
authors.initials: B
authors.lastname: Conijn
authors.forename: Hein
authors.initials: H
authors.lastname: De Vries
mesh_terms: D016739:Behavior, Addictive / Q000523:psychology / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D018579:Patient Selection; D015203:Reproducibility of Results; D012907:Smoking / Q000523:psychology*; D016540:Smoking Cessation / Q000379:methods* / Q000523:psychology; D014029:Tobacco Use Disorder / Q000523:psychology / Q000628:therapy*; D016896:Treatment Outcome