title: Non-response in a nationwide follow-up postal survey in Finland: a register-based mortality analysis of respondents and non-respondents of the Health and Social Support (HeSSup) Study.
abstract: OBJECTIVE
  To examine difference in mortality between postal survey non-respondents and respondents.
  
  
  METHODS
  A prospective cohort study with baseline survey in 1998 and comprehensive linkage to national mortality registers until 2005, the Health and Social Support study.
  
  
  METHODS
  A population-based postal survey of the working-aged population in Finland in 1998.
  
  
  METHODS
  The original random sample comprised 64 797 working-aged individuals in Finland (20-24, 30-34, 40-44, 50-54 years of age; 32 059 women and 32 716 men), yielding 25 898 (40.0%) responses in the baseline postal survey in 1998.
  
  
  METHODS
  Registry-based primary causes of death encoded with the International Classification of Diseases (ICD-10).
  
  
  RESULTS
  In women, HR for total mortality was 1.75 (95% CI 1.40 to 2.19) times higher among the non-respondents compared with the respondents. In men, non-response was associated with a 1.41-fold (1.21-1.65) excess risk of total mortality. Non-response associated in certain age groups with deaths due to diseases in women and with deaths due to external causes in men. The most prominent excess mortality was seen for total mortality for both genders and for mortality due to external causes among men.
  
  
  CONCLUSIONS
  Postal surveys result in slight underestimation of illness prevalence.
authors.affiliation: Department of Public Health, University of Turku, Turku, Finland.
authors.forename: Sakari
authors.initials: S
authors.lastname: Suominen
authors.forename: Karoliina
authors.initials: K
authors.lastname: Koskenvuo
authors.forename: Lauri
authors.initials: L
authors.lastname: Sillanmäki
authors.forename: Jussi
authors.initials: J
authors.lastname: Vahtera
authors.forename: Katariina
authors.initials: K
authors.lastname: Korkeila
authors.forename: Mika
authors.initials: M
authors.lastname: Kivimäki
authors.forename: Kari J
authors.initials: KJ
authors.lastname: Mattila
authors.forename: Pekka
authors.initials: P
authors.lastname: Virtanen
authors.forename: Markku
authors.initials: M
authors.lastname: Sumanen
authors.forename: Päivi
authors.initials: P
authors.lastname: Rautava
authors.forename: Markku
authors.initials: M
authors.lastname: Koskenvuo