title: Smoking cessation and quality of life: the effect of amount of smoking and time since quitting.
abstract: BACKGROUND
  Knowledge of the impact of smoking cessation on health-related quality of life may be important in encouraging smokers to quit. We determined whether the difference in quality of life between ex- and current smokers is influenced by amount of smoking or time since quitting.
  
  
  METHODS
  Data were collected within a cross-sectional study among a random sample of the general population in The Netherlands. Health-related quality of life was measured with the RAND-36 questionnaire (adapted from SF-36). Smoking behavior was assessed with a self-administered questionnaire. Adjusted differences in quality of life scores between ex- and current smokers were tested with multivariate analysis of variance, among 9,660 men and women aged 20-59 years, without history of tobacco-related chronic diseases.
  
  
  RESULTS
  Ex-smokers reported significantly higher quality of life scores than current smokers. This was more pronounced for mental health, especially for role functioning limitations due to emotional problems (difference 6.5 points; P < 0.0001), than for physical health dimensions. Differences were generally larger between ex- and current heavy smokers than between ex- and current light or moderate smokers (P trend <0.05 when ex-smokers had quit <5 or > or =10 years ago). No significant trend was observed with time since quitting.
  
  
  CONCLUSIONS
  Generally, the higher the amount of smoking, the higher were quality of life differences between ex- and current smokers.
authors.affiliation: Department of Chronic Diseases Epidemiology, National Institute of Public Health and the Environment, Bilthoven, The Netherlands.
authors.forename: I
authors.initials: I
authors.lastname: Mulder
authors.forename: M
authors.initials: M
authors.lastname: Tijhuis
authors.forename: H A
authors.initials: HA
authors.lastname: Smit
authors.forename: D
authors.initials: D
authors.lastname: Kromhout
mesh_terms: D000328:Adult; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D011788:Quality of Life; D016540:Smoking Cessation; D011795:Surveys and Questionnaires; D013997:Time Factors