title: Tobacco smoking surveillance: is quota sampling an efficient tool for monitoring national trends? A comparison with a random cross-sectional survey.
abstract: OBJECTIVE
  It is crucial for policy makers to monitor the evolution of tobacco smoking prevalence. In France, this monitoring is based on a series of cross-sectional general population surveys, the Health Barometers, conducted every five years and based on random samples. A methodological study has been carried out to assess the reliability of a monitoring system based on regular quota sampling surveys for smoking prevalence.
  In 2010, current and daily tobacco smoking prevalences obtained in a quota survey on 8,018 people were compared with those of the 2010 Health Barometer carried out on 27,653 people. Prevalences were assessed separately according to the telephone equipment of the interviewee (landline phone owner vs "mobile-only"), and logistic regressions were conducted in the pooled database to assess the impact of the telephone equipment and of the survey mode on the prevalences found. Finally, logistic regressions adjusted for sociodemographic characteristics were conducted in the random sample in order to determine the impact of the needed number of calls to interwiew "hard-to-reach" people on the prevalence found.
  
  
  RESULTS
  Current and daily prevalences were higher in the random sample (respectively 33.9% and 27.5% in 15-75 years-old) than in the quota sample (respectively 30.2% and 25.3%). In both surveys, current and daily prevalences were lower among landline phone owners (respectively 31.8% and 25.5% in the random sample and 28.9% and 24.0% in the quota survey). The required number of calls was slightly related to the smoking status after adjustment for sociodemographic characteristics.
  
  
  CONCLUSIONS
  Random sampling appears to be more effective than quota sampling, mainly by making it possible to interview hard-to-reach populations.
authors.affiliation: Scientific Affairs Department, National Institute for Health Promotion and Health Education (INPES), Saint-Denis, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Guignard
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Wilquin
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Richard
authors.forename: François
authors.initials: F
authors.lastname: Beck
mesh_terms: D003430:Cross-Sectional Studies; D015340:Epidemiologic Research Design; D062665:Epidemiological Monitoring; D005602:France / Q000453:epidemiology; D006801:Humans; D007407:Interviews as Topic; D016015:Logistic Models; D015995:Prevalence; D011897:Random Allocation; D012907:Smoking / Q000453:epidemiology*