title: Use of anchoring vignettes to evaluate health reporting behavior amongst adults aged 50 years and above in Africa and Asia--testing assumptions.
abstract: BACKGROUND
  Comparing self-rating health responses across individuals and cultures is misleading due to different reporting behaviors. Anchoring vignettes is a technique that allows identifying and adjusting self-rating responses for reporting heterogeneity (RH).
  
  
  OBJECTIVE
  This article aims to test two crucial assumptions of vignette equivalence (VE) and response consistency (RC) that are required to be met before vignettes can be used to adjust self-rating responses for RH.
  
  
  METHODS
  We used self-ratings, vignettes, and objective measures covering domains of mobility and cognition from the WHO study on global AGEing and adult health, administered to older adults aged 50 years and above from eight low- and middle-income countries in Africa and Asia. For VE, we specified a hierarchical ordered probit (HOPIT) model to test for equality of perceived vignette locations. For RC, we tested for equality of thresholds that are used to rate vignettes with thresholds derived from objective measures and used to rate their own health function.
  
  
  RESULTS
  There was evidence of RH in self-rating responses for difficulty in mobility and cognition. Assumptions of VE and RC between countries were violated driven by age, sex, and education. However, within a country context, assumption of VE was met in some countries (mainly in Africa, except Tanzania) and violated in others (mainly in Asia, except India).
  
  
  CONCLUSIONS
  We conclude that violation of assumptions of RC and VE precluded the use of anchoring vignettes to adjust self-rated responses for RH across countries in Asia and Africa.
authors.affiliation: Vadu Rural Health Program, KEM Hospital Research Centre, Pune, India. sidbela@vsnl.com
authors.forename: Siddhivinayak
authors.initials: S
authors.lastname: Hirve
authors.forename: Xavier
authors.initials: X
authors.lastname: Gómez-Olivé
authors.forename: Samuel
authors.initials: S
authors.lastname: Oti
authors.forename: Cornelius
authors.initials: C
authors.lastname: Debpuur
authors.forename: Sanjay
authors.initials: S
authors.lastname: Juvekar
authors.forename: Stephen
authors.initials: S
authors.lastname: Tollman
authors.forename: Yulia
authors.initials: Y
authors.lastname: Blomstedt
authors.forename: Stig
authors.initials: S
authors.lastname: Wall
authors.forename: Nawi
authors.initials: N
authors.lastname: Ng
mesh_terms: D000349:Africa; D000368:Aged; D001208:Asia; D003431:Cross-Cultural Comparison; D005260:Female; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D057566:Self Report; D012959:Socioeconomic Factors
keywords: anchoring vignettes; cognition; mobility; reporting heterogeneity; response consistency; self-rating; vignette equivalence