Social inequalities in mortality: a problem of cognitive function?

Abstract

Inequalities in health matter. The relationship between measures of socio-economic position and mortality is a strikingly consistent finding. It has been clear for some time that this relationship extends to cardiovascular mortality: a lower position in the social hierarchy is linked to higher mortality.1 It should give us pause. Much of medicine has to do with diagnosis and treatment of disease in individuals. This concern with individuals has been extended to prevention: use of the epidemiological data on risk factors as a basis for behaviour change or risk factor modification in individuals. Social inequalities in cardiovascular and other diseases suggest that we need to broaden our view. Action will require more than treatment of disease or of risk factors for disease in individual patients. But what to do? Knowing that there is a strong link between socio-economic position and mortality is relatively easy, and the effect size is large. The much harder questions are why and what to do about it. As David Batty and colleagues argue,2 the two questions are linked: understanding why is important for planning action to address these inequalities in health. When most people think about explanations for these social inequalities in health they think first of behaviours—smoking, diet, sedentary habits—and the consequent effect on risk factors. The study by Batty et al. confirms the importance of these risk factors in individuals. Nine cardiovascular risk factors—systolic and diastolic blood pressure, total and HDL cholesterol, body mass index (BMI), smoking, blood glucose, forced expiratory volume in 1 s (FEV1), and heart rate— accounted for ∼40% of social inequalities in mortality, … *Corresponding author. Tel: +44 20 7679 1694, Fax: +44 20 7813 0242, Email: m.marmot{at}ucl.ac.uk