Evaluating reporting heterogeneity in self-rated health among adults aged 50 years and above in India: an anchoring vignettes analytic approach

Abstract

Objective: To use anchoring vignettes to evaluate reporting heterogeneity (RH) in self-rated mobility and cognition in older adults.

Method: We analyzed vignettes and self-rated mobility and cognition in 2,558 individuals aged 50 years and above. We tested for assumptions of vignette equivalence (VE) and response consistency (RC). We used a joint hierarchical ordered probit (HOPIT) model to evaluate self-rating responses for RH.

Results: The assumption of VE was met except for "learning" vignettes. Higher socioeconomic status (SES) and education significantly lowered thresholds for cognition ratings. After correction for RH, women, lower SES, and older respondents were significantly more likely to report greater difficulty in mobility. The influence of age, SES, and education on thresholds was less apparent for cognition.

Discussion: Our study provides strong evidence of RH in self-rated mobility and cognition. We highlight the need to formally test basic assumptions before using vignettes to adjust self-rating responses for RH.

Keywords: India; anchoring vignettes; cognition; differential item functioning; mobility; reporting heterogeneity; self-rating.