Socioeconomic differences in smoking in an urban Swedish population. The bias introduced by non-participation in a mailed questionnaire

Scand J Soc Med. 1993 Jun;21(2):77-82. doi: 10.1177/140349489302100204.


Stockholm Health of the Population Study is a cross-sectional study carried out from 1984-85. Postal questionnaires, telephone interviews and health interviews were used to get information from a sample of 5,199 persons, 18-64 years of age, on health status, risk exposures, healthcare consumption and social factors. Non-participation with respect to the postal questionnaire was 36.8%. With subsequent telephone interviews and an invitation to a health interview, non-participation was reduced to 17.8%. The estimated prevalence of daily smoking increased from 36.1% to 38.7. The non-responders had a higher prevalence of daily smoking in all sub-groups. This effect of the efforts to reduce non-participation differed socially. The prevalence of smoking for men, 40-64 years of age, who were reached by telephone was 60.3%. Male professionals and intermediate non-manual workers, 40-64 years of age reached by telephone had a prevalence of smoking, which was twice as high as for the responders of the questionnaire (62.5 and 26.8%, respectively). In the younger age-group, non-responders had the same socioeconomic pattern in smoking as the responders. Independent of socioeconomic group, there was a tendency of ill or disabled smokers to respond more quickly than healthy smokers. Using a postal questionnaire with a high non-response rate might lead to an overestimation of socioeconomic differences and an underestimation of smoking prevalence.

MeSH terms

  • Adolescent
  • Adult
  • Cross-Sectional Studies
  • Female
  • Health Surveys
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Smoking / epidemiology*
  • Social Class
  • Socioeconomic Factors*
  • Sweden / epidemiology
  • Urban Population / statistics & numerical data*