title: [Reliability of a questionnaire on smoking to evaluate prevalence, knowledge and attitudes of medical students].
abstract: OBJECTIVE
  To evaluate the reliability and reproducibility of results obtained from a questionnaire on the smoking habits of medical students.
  
  
  METHODS
  A questionnaire with 30 variables was designed to measure three main parameters: prevalence, knowledge and attitudes toward smoking. First-year medical students at the University of Zaragoza (1997-98 academic year) were asked to fill in the questionnaire, and a code was assigned to each individual respondent. A test-retest method was then used to assess reliability: the same questionnaire was answered by the subjects after a period of time had elapsed. The Kappa coefficient was calculated to measure agreement.
  
  
  RESULTS
  The questionnaire was filled in by 181 students at registration and 7 weeks later by 43 students. The first- and second-time questionnaires for 35 individuals were matched by codes. Reliability was good for most variables related to the main characteristics of smoking (such as prevalence, number of cigarettes smoked daily and consonance-dissonance). Reliability was acceptable for most variables related to knowledge but was low for 3 items. Reliability was acceptable for half the items related to attitudes and low for half.
  
  
  CONCLUSIONS
  The questionnaire has a generally good level of reliability, with regard to reproducibility, or the likelihood that an individual will respond to an item in the same way at two different times. Some variables that measure attitudes toward smoking, however, are less reliable. Results obtained for those items should therefore be interpreted cautiously.
authors.affiliation: Unidad de Tabaquismo FMZ. Universidad de Zaragoza. Spain.
authors.forename: D
authors.initials: D
authors.lastname: Guillén
authors.forename: I
authors.initials: I
authors.lastname: Nerín
authors.forename: A
authors.initials: A
authors.lastname: Mas
authors.forename: A
authors.initials: A
authors.lastname: Crucelaegui
mesh_terms: D000328:Adult; D001294:Attitude to Health; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D009042:Motivation; D015995:Prevalence; D015203:Reproducibility of Results; D012907:Smoking / Q000453:epidemiology*; D016540:Smoking Cessation / Q000706:statistics & numerical data; D013337:Students, Medical / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires
vernacular_title: Estudio de fiabilidad de una encuesta utilizada para valorar la prevalencia, los conocimientos y las actitudes sobre el tabaquismo en estudiantes de medicina.