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The Study on global AGEing and adult health (SAGE) aims at improving empirical understanding of the health and well-being of older adults in low- and middle-income countries. A total of 321 adults aged 50 years and older were interviewed in rural Pune district, India, in 2007. We used Structural Equation Modelling (SEM) to examine the pathways through which social factors, functional disability, risk behaviours, and chronic disease experience influence self-rated health (SRH) and quality of life (QOL) amongst older adults in India. Both SRH and QOL worsened with increased age (indirect effect) and limitations in functional ability (direct effect). QOL, socio-economic status (SES), and social networking had no significant effect on SRH. Smoking was associated with the presence of at least one chronic illness, but this did not have a statistically significant effect on SRH. Higher social networking was seen amongst the better educated and those with regular income, which in turn positively affected the QOL rating. QOL had a direct, but statistically not significant, effect on SRH. In conclusion, the indirect effects of age on SRH mediated through functional ability, and the effects of SES on QOL mediated through social networking, provide new understanding of how age and socio-economic status affect SRH and QOL. By allowing for measurement errors, solving for collinearity in predictor variables by integrating them into measurement models, and specifying causal dependencies between the underlying latent constructs, SEM provides a strong link between theory and empirics.

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.

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.

We compared prevalence estimates of self-rated health (SRH) derived indirectly using four different small area estimation methods for the Vadu (small) area from the national Study on Global AGEing (SAGE) survey with estimates derived directly from the Vadu SAGE survey. The indirect synthetic estimate for Vadu was 24% whereas the model based estimates were 45.6% and 45.7% with smaller prediction errors and comparable to the direct survey estimate of 50%. The model based techniques were better suited to estimate the prevalence of SRH than the indirect synthetic method. We conclude that a simplified mixed effects regression model can produce valid small area estimates of SRH.