title: Treated individuals who progress to action or maintenance for one behavior are more likely to make similar progress on another behavior: coaction results of a pooled data analysis of three trials.
abstract: OBJECTIVE
  This study compared, in treatment and control groups, the phenomena of coaction, which is the probability that taking effective action on one behavior is related to taking effective action on a second behavior.
  
  
  METHODS
  Pooled data from three randomized trials of Transtheoretical Model (TTM) tailored interventions (n=9461), completed in the U.S. in 1999, were analyzed to assess coaction in three behavior pairs (diet and sun protection, diet and smoking, and sun protection and smoking). Odds ratios (ORs) compared the likelihood of taking action on a second behavior compared to taking action on only one behavior.
  
  
  RESULTS
  Across behavior pairs, at 12 and 24 months, the ORs for the treatment group were greater on an absolute basis than for the control group, with two being significant. The combined ORs at 12 and 24 months, respectively, were 1.63 and 1.85 for treatment and 1.20 and 1.10 for control.
  
  
  CONCLUSIONS
  The results of this study with addictive, energy balance and appearance-related behaviors were consistent with results found in three studies applying TTM tailoring to energy balance behaviors. Across studies, there was more coaction within the treatment group. Future research should identify predictors of coaction in more multiple behavior change interventions.
authors.affiliation: Cancer Prevention Research Center, University of Rhode Island, Kingston, RI 02881, USA. apaiva@uri.edu
authors.forename: Andrea L
authors.initials: AL
authors.lastname: Paiva
authors.forename: James O
authors.initials: JO
authors.lastname: Prochaska
authors.forename: Hui-Qing
authors.initials: HQ
authors.lastname: Yin
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Rossi
authors.forename: Colleen A
authors.initials: CA
authors.lastname: Redding
authors.forename: Bryan
authors.initials: B
authors.lastname: Blissmer
authors.forename: Mark L
authors.initials: ML
authors.lastname: Robbins
authors.forename: Wayne F
authors.initials: WF
authors.lastname: Velicer
authors.forename: Jessica
authors.initials: J
authors.lastname: Lipschitz
authors.forename: Nicole
authors.initials: N
authors.lastname: Amoyal
authors.forename: Steven F
authors.initials: SF
authors.lastname: Babbin
authors.forename: Cerissa L
authors.initials: CL
authors.lastname: Blaney
authors.forename: Marie A
authors.initials: MA
authors.lastname: Sillice
authors.forename: Anne
authors.initials: A
authors.lastname: Fernandez
authors.forename: Heather
authors.initials: H
authors.lastname: McGee
authors.forename: Satoshi
authors.initials: S
authors.lastname: Horiuchi
mesh_terms: D000328:Adult; D004032:Diet; D005260:Female; D015438:Health Behavior; D006293:Health Promotion / Q000379:methods; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D011481:Protective Clothing; D012237:Rhode Island; D012878:Skin Neoplasms / Q000517:prevention & control*; D012907:Smoking; D012931:Social Environment; D059405:Sun Protection Factor