title: Context effects in survey ratings of health, symptoms, and satisfaction.
abstract: BACKGROUND
  Survey self-reports of health status, symptoms (pain and fatigue), and life satisfaction often serve as outcomes in clinical trials. Prior studies have shown, however, that such reports can be subject to context effects, which could threaten their validity.
  
  
  METHODS
  We examined the impact of 2 context effects: the effect of the reporting period associated with a question (No Period Specified; Last Month; Right Now) and the effect of whom the respondent compared themselves to in answering a question (None Specified; Compared with Others in the US; Compared with 20-Year-Olds).
  
  
  RESULTS
  One thousand four hundred seventy-one community adults aged 20 through 70 years, who were members of an internet panel, responded to 1 of 9 questionnaires formed by crossing the 2 context variables. A significant effect of Reporting Period was observed indicating that higher levels of Pain and Fatigue were associated with the 1-Month reporting period. When no reporting period was specified, symptom levels were equivalent to the Right Now levels of symptoms. Reporting Period had no effect on the other outcomes. Educational level did not interact with these main effects, with 1 exception. None of the predicted effects were found for Comparison Group, although Pain was significantly associated with this factor.
  
  
  CONCLUSIONS
  Reporting period in survey questions is a factor that influences responses and should be considered by survey researchers in their study designs.
authors.affiliation: Department of Psychiatry and Behavioral Science, Stony Brook University, Stony Brook, New York 11994-8790, USA. arthur.stone@sunysb.edu
authors.forename: Arthur A
authors.initials: AA
authors.lastname: Stone
authors.forename: Joan E
authors.initials: JE
authors.lastname: Broderick
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Schwartz
authors.forename: Norbert
authors.initials: N
authors.lastname: Schwarz
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D019538:Health Care Surveys / Q000379:methods / Q000592:standards*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires