title: A randomized, controlled trial of adding expired carbon monoxide feedback to brief stop smoking advice: evaluation of cognitive and behavioral effects.
abstract: OBJECTIVE
  To determine the effect of adding biomarker feedback (expired air carbon monoxide) to standard quit advice on cognitive antecedents of behavior change and smoking cessation and to identify potential effect moderators and mediators.
  
  
  METHODS
  Smokers (N = 160) were randomized to a control (quit advice plus leaflet) or an intervention condition (as control group plus carbon-monoxide level feedback). Cognitive measures were assessed immediately after the intervention and behavioral measures at 6 months' follow-up.
  
  
  METHODS
  Primary outcome measures were threat and efficacy appraisal, fear arousal, and intention to stop smoking. Secondary outcome measures were quit attempts within the last 6 months and 7-day point prevalence abstinence.
  
  
  RESULTS
  Threat appraisal was significantly enhanced in the intervention compared with the control group, t(158) = 2.29, p = .023, as was intention to stop smoking in the next month, t(151) = 2.9, p = .004. However, this effect on intention to stop smoking was short-lived. Groups did not differ in terms of quit attempts or abstinence at follow-up, but the intervention increased the likelihood of cessation in smokers with higher self-efficacy, χ2(1) = 5.82, p = .016.
  
  
  CONCLUSIONS
  Carbon-monoxide level feedback enhances the effect of brief quit advice on cognitive antecedents of behavior change and smoking cessation rates but further research is required to confirm the longevity of this effect and its applicability to smokers with low self-efficacy.
authors.affiliation: Cancer Research UK Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, 2-16 Torrington Place, London, UK. lion.shahab@ucl.ac.uk
authors.forename: Lion
authors.initials: L
authors.lastname: Shahab
authors.forename: Robert
authors.initials: R
authors.lastname: West
authors.forename: Ann
authors.initials: A
authors.lastname: McNeill
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers; D001944:Breath Tests; D002248:Carbon Monoxide / Q000032:analysis*; D045853:Exhalation; D005246:Feedback; D005260:Female; D006801:Humans; D008131:London; D008297:Male; D008875:Middle Aged; D012907:Smoking / Q000628:therapy*; D016540:Smoking Cessation / Q000379:methods*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D002248:Carbon Monoxide