title: Assessment of the validity of self-reported smoking status among schoolchildren in Sousse, Tunisia.
abstract: BACKGROUND
  Tobacco use, which begins in adolescence and childhood and continues in later life, is the major avoidable risk for non-communicable diseases and death in the world. Self-reports have frequently been used to estimate smoking prevalence and health consequences. This study explores the validity of self-reports of smoking behavior among schoolchildren in Tunisia.
  
  
  METHODS
  This study was conducted in March 2014 among a sample of 147 schoolchildren randomly selected. Data concerning the smoking habit were collected by a questionnaire designed for the purposes of this work. Then, exhaled CO, a biochemical marker of smoke exposure, was measured using piCO+ Smokerlyzer® breath CO monitor among participants. Sensitivity and specificity of self-reports were calculated.
  
  
  RESULTS
  The prevalence of reported smoking was 9.5% with 16.7% and 1.7% respectively among boys and girls. Their mean age was 14.5±1.28 years old. When considering 4 ppm as the cut-off level of breath CO, sensitivity and specificity of self-reports were 100% and 93.7%, respectively. But at a breath CO cut-off of 3 ppm, self-reporting was 62.5% sensitive and 93.5% specific.
  
  
  CONCLUSIONS
  According to our findings, we suggest that self-reports can be considered as a good tool to be used with a reasonable confidence to assess the smoking status.
authors.forename: Jihene
authors.initials: J
authors.lastname: Maatoug
authors.forename: Jihene
authors.initials: J
authors.lastname: Sahli
authors.forename: Imed
authors.initials: I
authors.lastname: Harrabi
authors.forename: Firas
authors.initials: F
authors.lastname: Chouikha
authors.forename: Sonia
authors.initials: S
authors.lastname: Hmad
authors.forename: Emna
authors.initials: E
authors.lastname: Dendana
authors.forename: Sihem Ben
authors.initials: SB
authors.lastname: Fredj
authors.forename: Slim
authors.initials: S
authors.lastname: Slama
authors.forename: Mustafa
authors.initials: M
authors.lastname: al'Absi
authors.forename: Harry
authors.initials: H
authors.lastname: Lando
authors.forename: Hassen
authors.initials: H
authors.lastname: Ghannem
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000032:analysis; D002248:Carbon Monoxide / Q000032:analysis; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D015995:Prevalence; D012574:Schools; D057566:Self Report / Q000592:standards*; D012907:Smoking / Q000453:epidemiology*; D013334:Students; D011795:Surveys and Questionnaires / Q000592:standards*; D014416:Tunisia / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D002248:Carbon Monoxide