Self-rated literacy level does not explain educational differences in health and disease

BACKGROUND Although literacy is increasingly considered to play a role in socioeconomic inequalities in health, its contribution to the explanation of educational differences in health has remained unexplored. The aim of this study was to investigate the contribution of self-rated literacy to educational differences in health. METHODS Data was collected from the Healthy Foundation and Lifestyle Segmentation Dataset (n = 4257). Self-rated literacy was estimated by individuals' self-reported confidence in reading written English. We used logistic regression analyses to assess the association between educational level and health (long term conditions and self-rated health). Self-rated literacy and other potential explanatory variables were separately added to each model. For each added variable we calculated the percentage change in odds ratio to assess the contribution to the explanation of educational differences in health. RESULTS People with lower educational attainment level were more likely to report a long term condition (OR 2.04, CI 1.80-2.32). These educational differences could mostly be explained by age (OR decreased by 27%) and could only minimally be explained by self-rated literacy, as measured by self-rated reading skills (OR decreased by 1%). Literacy could not explain differences in cardiovascular condition or diabetes, and only minimally contributed to mental health problems and depression (OR decreased by 5%). The odds of rating ones own health more negatively was higher for people with a low educational level compared to those with a higher educational level (OR 1.83, CI 1.59-2.010), self-rated literacy decreased the OR by 7%. CONCLUSION Measuring self-rated reading skills does not contribute significantly to the explanation of educational differences in health and disease. Further research should aim for the development of objective generic and specific instruments to measure health literacy skills in the context of health care, disease prevention and health promotion. Such instruments are not only important in the explanation of educational differences in health and disease, but can also be used to identify a group at risk of poorer health through low basic skills, enabling health services and health information to be targeted at those with greater need.