title: Mediators of a successful web-based smokeless tobacco cessation program.
abstract: OBJECTIVE
  To examine self-efficacy and program exposure as possible mediators observed treatment effects for a web-based tobacco cessation intervention.
  
  
  METHODS
  The ChewFree trial used a two-arm design to compare tobacco abstinence at both the 3- and 6-month follow-up for participants randomized to either an enhanced intervention condition or a basic information-only control condition.
  
  
  METHODS
  Internet in US and Canada.
  
  
  METHODS
  Our secondary analyses focused upon 402 participants who visited the web-based program at least once, whose baseline self-efficacy rating showed room for improvement, who reported that they were still using tobacco at the 6-week assessment, and for whom both 3- and 6-month follow-up data were available.
  
  
  METHODS
  An enhanced web-based behavioral smokeless tobacco cessation intervention delivered program content using text, interactive activities, testimonial videos and an ask-an-expert forum and a peer forum. The basic control condition delivered tobacco cessation content using static text only.
  
  
  METHODS
  Change in self-efficacy and program exposure from baseline to 6 weeks were tested as simple and multiple mediators on the effect of treatment condition on point-prevalence tobacco abstinence measured at 3- and 6-month follow-up.
  
  
  RESULTS
  While both participant self-efficacy and program exposure satisfied the requirements for simple mediation, only self-efficacy emerged as a mediator when we used the more robust test of multiple mediation.
  
  
  CONCLUSIONS
  Results confirm the importance of self-efficacy change as a probable underlying mechanism in a successful web-based behavioral intervention. While program exposure was found to be a simple mediator of tobacco abstinence, it failed to emerge as a mediator when tested with self-efficacy change in a multiple mediator test suggesting that self-efficacy and program exposure share a complex, possibly reciprocal relationship with the tobacco abstinence outcome. Our results underscore the utility of searching for mediators in research on web-based interventions.
authors: Oregon Research Institute, Eugene, OR 97403, USA. briand@ori.org
authors: Brian G
authors: BG
authors: Danaher
authors: Keith
authors: K
authors: Smolkowski
authors: John R
authors: JR
authors: Seeley
authors: Herbert H
authors: HH
authors: Severson
mesh_terms: D000328:Adult; D001521:Behavior Therapy / Q000379:methods; D002170:Canada; D005500:Follow-Up Studies; D015438:Health Behavior; D006801:Humans; D020407:Internet; D010349:Patient Compliance / Q000706:statistics & numerical data*; D015397:Program Evaluation; D020377:Self Efficacy; D013813:Therapy, Computer-Assisted / Q000379:methods*; D020340:Tobacco Use Cessation / Q000379:methods* / Q000523:psychology; D014030:Tobacco, Smokeless; D014481:United States