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

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.

Does self-rated health predict death in adults aged 50 years and above in India? Evidence from a rural population under health and demographic surveillance.

BACKGROUND: The Study on Global Ageing and Adult Health (SAGE) aims to improve empirical understanding of health and well-being of adults in developing countries. We examine the role of self-rated health (SRH) in predicting mortality and assess how socio-demographic and other disability measures influence this association. METHODS: In 2007, a shortened SAGE questionnaire was administered to 5087 adults aged ≥50 years under the Health Demographic Surveillance System in rural Pune district, India. Respondents rated their own health with a single global question on SRH. Disability and well-being were assessed using the WHO Disability Assessment Schedule Index, Health State Score and quality-of-life score. Respondents were followed up every 6 months till June 2011. Any change in spousal support, migration or death during follow-up was updated in the SAGE dataset. RESULTS: In all, 410 respondents (8%) died in the 3-year follow-up period. Mortality risk was higher with bad/very bad SRH [hazard ratio (HR) in men: 3.06, 95% confidence interval (CI): 1.93-4.87; HR in women: 1.64, 95% CI: 0.94-2.86], independent of age, disability and other covariates. Disability measure (WHO Disability Assessment Schedule Index) and absence of spousal support were also associated with increased mortality risk. CONCLUSION: Our findings confirm an association between bad/very bad SRH and mortality for men, independent of age, socio-demographic factors and other disability measures, in a rural Indian population. This association loses significance in women when adjusted for disability. Our study highlights the strength of nesting cross-sectional surveys within the context of the Health Demographic Surveillance System in studying the role of SRH and mortality.