title: Responders and non-responders in a study on medical end-of-life decisions in Denmark, the Netherlands, Sweden and Switzerland.
abstract: OBJECTIVE
  To determine the direction and magnitude of participation bias in end-of-life research.
  
  
  METHODS
  Within the framework of a European survey on medical end-of-life decisions, a non-response study was conducted among physicians in Denmark, the Netherlands, Sweden and Switzerland. People were asked about their attitudes and experiences in the area of medial end-of-life decision. The response rates ranged from 12.8% (Netherlands) to 39.4% (Switzerland). The responders (n = 5403) and the non-responders (n = 866) were compared regarding socio-demographic characteristics, experiences with terminal patients and agreement with attitudes towards "end-of-life decisions". The reasons for non-participation to the study were analyzed.
  
  
  RESULTS
  Non-response did not cause socio-demographic distortion, but non-responders had statistically significantly fewer terminal patients than responders. Agreement rates were statistically significantly higher among responders than among non-responders for euthanasia, non-treatment decision and life-preserving statements. Neutral answers were statistically significantly more frequent among non-responders than among responders for life-preserving and euthanasia statements. The most commonly mentioned reason for non-participation was "lack of time".
  
  
  CONCLUSIONS
  Non-participation does cause an overestimation of proponents of life-shortening, as well as of life-preserving end-of-life decisions. Non-responders more often have ambiguous attitudes towards end-of-life decisions than responders.
authors.affiliation: Institute of Sociology, University of Zurich, Switzerland. susanne.fischer@soziologie.unizh.ch
authors.forename: Susanne
authors.initials: S
authors.lastname: Fischer
authors.forename: Guido
authors.initials: G
authors.lastname: Miccinesi
authors.forename: Rainer
authors.initials: R
authors.lastname: Hornung
authors.forename: Georg
authors.initials: G
authors.lastname: Bosshard
authors.forename: Luc
authors.initials: L
authors.lastname: Deliens
authors.forename: Agnes
authors.initials: A
authors.lastname: van der Heide
authors.forename: Tore
authors.initials: T
authors.lastname: Nilstun
authors.forename: Michael
authors.initials: M
authors.lastname: Norup
authors.forename: Bregje D
authors.initials: BD
authors.lastname: Onwuteaka-Philipsen
mesh_terms: D000328:Adult; D016223:Advance Directives / Q000523:psychology / Q000706:statistics & numerical data*; D001291:Attitude of Health Personnel; D015982:Bias; D003657:Decision Making; D005060:Europe; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D010820:Physicians / Q000523:psychology / Q000706:statistics & numerical data; D045808:Refusal to Participate / Q000523:psychology / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires; D013727:Terminal Care / Q000706:statistics & numerical data