Differential health reporting by education level and its impact on the measurement of health inequalities among older Europeans
Background: The purpose of this study is to establish whether the reporting of health differs by education level and, if so, to determine the extent to which this biases the measurement ofhealth inequalities among older Europeans.Methods: Data are from the Survey of Health, Ageing and Retirement in Europe (SHARE) covering eight countries. Differential reporting of health by education is identified from ratings of anchoring vignettes that describe fixed health states. Ratings of own health in sixdomains (mobility, pain, sleep, breathing, emotional health, cognition) are corrected for differences in reporting using an extended ordered probit model. For each country and healthdomain, we compare the corrected with the uncorrected age-sex standardised high to low education rate ratio for the absence of a health problem.Results: Before correction for reporting differences, there is no significant disparity in health by education in 32 of 48 cases. There is a significant difference in reporting of health by education in 29 cases. Correcting for these differences generally increases health disparities (except for Spain and Sweden) and results in the emergence of significant inequalities in 18 cases. The greatest impact is in Belgium, Germany and The Netherlands, where disparitiesbecome significant only after adjustment in four of the six health domains.Conclusions: Higher educated older Europeans are more likely to rate a given health state negatively. As a result, measured health inequalities by education are often underestimated,and even go undetected, if no account is taken of these reporting differences.