title: Health survey: comparison of interviewees according to ownership of a residential telephone line.
abstract: OBJECTIVE
  To analyze differences in sociodemographic characteristics associated with health in individuals with and without a residential telephone line.
  
  
  METHODS
  Data from the ISA-Capital 2003 (2003 Health Survey), a study performed in the city of São Paulo, Southeastern Brazil, were analyzed. Residents who had a residential telephone line were compared to those who reported not having a telephone line, according to sociodemographic, lifestyle, health status and health service use variables. Bias associated with non-coverage of the population without a telephone line was estimated, decreasing after the use of post-stratification adjustments.
  
  
  RESULTS
  Of all the 1,878 interviewees aged more than 18 years, 80.1% had a residential telephone line. By comparing groups, the main sociodemographic differences among individuals who did not have a residential telephone line were the following: younger age, greater proportion of black and mixed individuals, smaller proportion of married interviewees, and greater proportion of unemployed individuals with a lower level of education. Residents without a residential telephone line had fewer health tests performed and smoked and drank more. In addition, this group took less medication, considered themselves to be in worse health conditions and used the SUS (National Health System) more frequently. When excluding the population without a telephone line from the analysis, estimates of dental consultations, alcoholism, drug use and SUS use to have a Papanicolaou test performed were those showing the highest bias. After post-stratification adjustment, there was a decrease in the bias of estimates for the variables associated with ownership of a residential telephone line.
  
  
  CONCLUSIONS
  The exclusion of residents without a telephone line was one of the main limitations to the studies performed in this way. However, the use of statistical techniques of post-stratification adjustment enables a reduction in non-coverage bias.
authors.affiliation: Departamento de Epidemiologia, Universidade de São Paulo, São Paulo, SP, Brazil. neuber@usp.br
authors.forename: Neuber José
authors.initials: NJ
authors.lastname: Segri
authors.forename: Chester Luiz Galvão
authors.initials: CL
authors.lastname: Cesar
authors.forename: Marilisa Berti de Azevedo
authors.initials: MB
authors.lastname: Barros
authors.forename: Maria Cecilia Goi Porto
authors.initials: MC
authors.lastname: Alves
authors.forename: Luana
authors.initials: L
authors.lastname: Carandina
authors.forename: Moisés
authors.initials: M
authors.lastname: Goldbaum
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001938:Brazil; D003430:Cross-Sectional Studies; D005260:Female; D006296:Health Services / Q000706:statistics & numerical data*; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D010067:Ownership; D012959:Socioeconomic Factors; D013689:Telephone / Q000706:statistics & numerical data*; D055815:Young Adult