Assessing the Effectiveness of Anchoring Vignettes in Bias Reduction for Socioeconomic Disparities in Self-Rated Health among Chinese Adults.

This study investigates how reporting heterogeneity may bias socioeconomic and demographic disparities in self-rated general health, a widely used health indicator, and how such bias can be adjusted by using new anchoring vignettes designed in the 2012 wave of the China Family Panel Studies (CFPS). We find systematic variation by socio-demographic characteristics in thresholds used by respondents in rating their general health status. Such threshold shifts are often non-parallel in that the effect of a certain group characteristic on the shift is stronger at one level than another. We find that the resulting bias of measuring group differentials in self-rated health can be too substantial to be ignored. We demonstrate that the CFPS anchoring vignettes prove to be an effective survey instrument in obtaining bias-adjusted estimates of health disparities not only for the CFPS sample, but also for an independent sample from the China Health and Retirement Longitudinal Study. Effective adjustment for reporting heterogeneity may require vignette administration only to a small subsample (20-30% of the full sample). Using a single vignette can be as effective as using more in terms of anchoring, but the results are sensitive to the choice of vignette design.