Does socioeconomic status modify how individuals perceive or describe their own health? An assessment of reporting heterogeneity in the Health Survey for England.

Background: Self-reported health (SRH) is widely used as a proxy for health status; it is a simple, holistic measure of health and has been associated with other health outcomes. However, variation in these associations has been found by subgroup, leaving open the possibility of systematic reporting differences, including by socioeconomic status. Methods: Using data from the 2017 and 2018 waves of the Health Survey for England, we assessed the relationship between deprivation quintile and SRH using multiple linear regression models for EQ-5D score, a health-related quality of life measure. Reporting heterogeneity between deprivation quintiles was assessed by the significance of model interaction terms. Analyses were stratified by sex and accounted for age group, ethnicity, marital status and religion (females only). Results: Significant interactions were found between deprivation quintile and SRH in the models for EQ-5D score for participants reporting poor health in the two most deprived quintiles, with coefficients ranging from -0.041 to -0.098. The largest differences were in the second most deprived quintile for men (-0.075, 95% CI: -0.110 to -0.040, p<0.001) and the most deprived quintile for women (-0.098, 95% CI: -0.128 to -0.067, p<0.001). Secondary analyses using body mass index as the response variable, for models structured in a similar way to those for EQ-5D, found no significant interaction terms between deprivation quintile and SRH. Conclusions: This analysis suggests that people from more deprived areas who report themselves to be in poor health may have worse health, as measured by EQ-5D, than those from less deprived areas. This could lead to an underestimation of health inequalities, including in measures, such as healthy life expectancy in England, that incorporate SRH data.