Patterns of class inequality in health through the lifespan: class gradients at 15, 35 and 55 years in the west of Scotland.

Data confirming the existence of social inequalities in health have continued to accumulate since the Black Report reported class inequalities across a broad range of causes of mortality, with an increasing emphasis on indicators of morbidity and current health status. Although evidence of continuing inequalities mounts, elucidation of underlying mechanisms generating and maintaining such inequalities has been more elusive, and much of the debate has oscillated from the very broad to the very specific. In this paper, the class patterning of a range of non-fatal indicators of health are modelled in an attempt to outline first the adequacy of models of linear relationships for this range of measures, and secondly, the extent to which these are generalizable across a series of age/sex subgroups and across different domains of health. Data are presented here for representative community samples of men and women in adolescence, early- and late-midlife. While orderly relationships between social class and health were seen for the majority of the measures considered; the detailed patterns show considerable diversity. Thus for some aspects of health, notably height (itself often heralded as a broad indicator of health and early life experience), common class gradients were observed for both sexes at each of the stages of the life course examined. For others (notably mental health and presence of chronic illness), gradients were evident in later life but not in adolescence. Others still showed sex but not age differences in class patterning (typically measures of body shape), or no clear patterns (notably blood pressure and consultations with general practitioners). The current analysis draws attention to the consistency of gradients in early- and late-midlife, which are apparent despite the marked increase in the burden of poorer health which manifests between these life stages for almost all indicators of health (an exception being mental health). The challenges which this presents for understanding the mechanisms and processes which have been candidate explanations for social inequalities in health are discussed.