title: Concordance between timeline follow-back and single-question assessment of self-reported smoking in a clinical trial.
abstract: Smoking cessation clinical trials assess tobacco abstinence using self-report and biomarkers. Optimum methods for each are unclear; a common question assesses smoking in the prior 7 days. In contrast, timeline follow-back (TLFB) is another technique often used to assess use of alcohol in treatment trials; it is used less frequently in studies of smoking cessation. The goal of this study was to assess concordance between the 7-day smoking question and a 7-day TLFB.
  
  
  
  Secondary analysis of data from a randomized clinical trial of smoking cessation was conducted at a busy, urban hospital emergency department (ED) from October 2010 to December 2012. At 1, 3, and 12 months, subjects were contacted by phone to assess smoking status. Those reporting abstinence at 3 months were asked to return for an in-person measurement of exhaled carbon monoxide. For this analysis, smoking status at 1 month was compared for subjects in response to 2 questions asked concurrently, addressing 7-day point prevalence tobacco use and a 7-day TLFB.
  
  
  
  Of 780 subjects, 666 (85.4%) were available for 1-month follow-up. Of these, 99 (14.9%) reported no smoking in response to the 7-day question, and 96 (14.4%) reported no smoking in response to the 7-day TLFB. The overall proportionate agreement between the 2 methods was 98.6%, with a kappa of 0.95 (95% confidence interval [CI]: 0.91-0.98).
  
  
  
  A single question that assesses smoking at 7 days provides excellent concordance with the more detailed TLFB. The single question appears adequate to assess self-reported tobacco use in clinical trials of smoking cessation.
authors.affiliation: a Department of Emergency Medicine , Yale School of Medicine , New Haven , Connecticut , USA.|b Yale Cancer Center, Yale School of Medicine , New Haven , Connecticut , USA.|c Department of Health Policy , Yale School of Public Health , New Haven , Connecticut , USA.
authors.forename: Steven L
authors.initials: SL
authors.lastname: Bernstein
authors.affiliation: a Department of Emergency Medicine , Yale School of Medicine , New Haven , Connecticut , USA.
authors.forename: June
authors.initials: J
authors.lastname: Rosner
authors.affiliation: b Yale Cancer Center, Yale School of Medicine , New Haven , Connecticut , USA.|d Department of Psychiatry , Yale School of Medicine , New Haven , Connecticut , USA.|e Medical University of South Carolina , Charleston , South Carolina , USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Toll
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D009511:New England / Q000453:epidemiology; D016032:Randomized Controlled Trials as Topic / Q000379:methods*; D057566:Self Report; D012907:Smoking / Q000453:epidemiology*; D016540:Smoking Cessation / Q000379:methods*; D013997:Time Factors; D055815:Young Adult
keywords: Smoking cessation; timeline follow-back; tobacco abstinence