title: Smoke or fog? The usefulness of retrospectively reported information about smoking.
abstract: OBJECTIVE
  To investigate the reliability and validity of retrospectively reported information on smoking.
  
  
  METHODS
  Nationally representative retrospective data from longitudinal surveys and contemporaneous data from repeated cross-sectional surveys were used.
  
  
  METHODS
  Adult respondents to three of the four samples of the National Longitudinal Surveys Original Cohort 1966-68; the National Longitudinal Survey of Youth 1979; and various waves of the US National Health Interview Survey.
  
  
  METHODS
  Reliability was investigated by calculating kappa statistics for repeated measures of ever-smoking and annual-smoking status. Validity was investigated by comparing smoking prevalence rates generated by retrospective data with contemporaneously measured rates.
  
  
  RESULTS
  Kappa statistics indicated the repeated measures of ever-smoking status show substantial agreement; repeated measures of annual-smoking status show moderate agreement. Retrospective reports on smoking behavior produced prevalence rates that match reasonably well with those from contemporaneous reports of smoking behavior.
  
  
  CONCLUSIONS
  Retrospective data on smoking can be an important resource for tobacco addiction research.
authors.affiliation: Department of Policy Analysis and Management, Cornell University, Ithaca, NY 14853-4401, USA. dsk10@cornell.edu
authors.forename: Donald
authors.initials: D
authors.lastname: Kenkel
authors.forename: Dean R
authors.initials: DR
authors.lastname: Lillard
authors.forename: Alan
authors.initials: A
authors.lastname: Mathios
mesh_terms: D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012907:Smoking / Q000453:epidemiology*