The focus of this research programme is on the explanation of patterns of disease and mortality in populations. Three questions are addressed: - How can (changes in) patterns of disease and mortality be measured effectively? - What factors determine these (changes in) patterns? - To what extent can health policy influence these patterns of disease and mortality? Four groups of determinants are being studied: - social factors, such as socioeconomic status and marital status; - demographic factors, such as ageing; - work-related factors; - medical care.