title: Use of non-assigned interventions in a randomized trial of internet and telephone treatment for smoking cessation.
abstract: BACKGROUND
  A recent meta-analysis of Internet interventions for smoking cessation found mixed evidence regarding effectiveness. One explanation may be differential use of non-assigned cessation treatments-including other Internet programs-that either amplify or mask study intervention effects. We examined the impact of non-assigned treatment use on cessation outcomes in The iQUITT Study, a randomized trial of Internet and telephone treatment for smoking cessation.
  
  
  METHODS
  Participants were randomized to a basic Internet (BI) comparison condition (N = 675), enhanced Internet (EI: N = 651), or EI plus telephone counseling (EI+P: N = 679). The primary outcome was 30-day point prevalence abstinence (ppa) at 3 and 6 months. Assigned intervention use was assessed with automated tracking data. Assessment of non-assigned treatments included pharmacotherapy, behavioral, alternative, and non-study Internet treatments. Univariate and multivariate logistic regression models examined whether non-assigned treatment use was associated with 30-day ppa.
  
  
  RESULTS
  About 70% of participants used at least one non-assigned treatment. A higher rate of non-study Internet treatment among BI participants was the only treatment group difference at both 3 and 6 months. Multivariate models controlling for condition and baseline predictors of non-assigned treatment use showed that high-intensity non-study Internet treatment was positively associated with 30-day ppa at 3 and 6 months, and pharmacotherapy and behavioral treatment use was negatively associated with 30-day ppa at 6 months.
  
  
  CONCLUSIONS
  Non-assigned treatment use is an important factor to consider when evaluating Internet cessation interventions. Results highlight methodological issues in selecting a comparison condition. Researchers should report non-assigned treatment use alongside main trial outcomes.
authors.affiliation: Schroeder Institute for Tobacco Research and Policy Studies, Legacy, Washington, DC;
authors.forename: Caroline O
authors.initials: CO
authors.lastname: Cobb
authors.affiliation: Schroeder Institute for Tobacco Research and Policy Studies, Legacy, Washington, DC; Department of Oncology, Georgetown University Medical Center/Cancer Prevention and Control Program, Lombardi Comprehensive Cancer Center, Washington, DC agraham@legacyforhealth.org.
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Graham
mesh_terms: D003376:Counseling / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020407:Internet / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D012907:Smoking / Q000523:psychology / Q000628:therapy*; D016540:Smoking Cessation / Q000379:methods* / Q000523:psychology; D013689:Telephone / Q000706:statistics & numerical data*; D013813:Therapy, Computer-Assisted / Q000379:methods; D016896:Treatment Outcome