Background: The aim of this study was to determine the relationship between household income and measures of health at different points in the life course. Method: Analysis of second-wave data collected in 1990-1991 in a longitudinal study of three age cohorts (15, 35 and 55 years in 1987-1988) in the West of Scotland was performed. The subjects were 851 18 year olds, 801 39 year olds and 761 58 year olds on whom data on income and a range of health measures were available (92% of those interviewed in 1990-1991). Results: Blood pressure was not significantly related to household income. Height, weight, waist:hip ratio, body mass index, pulse rate, long-standing illness and limiting long-standing illness showed linear associations with household income and FEV1/height(2), number of recent malaise symptoms reported, number of checklist of 22 recent symptoms reported, GHQ scores and self-assessed health had curvilinear relationships with household income. There were interactions between income and sex for weight, waist:hip ratio, BMI and pulse rate and interactions between income and age for malaise, symptom checklist and self-assessed health. A threshold model of the relationship between income and health was not supported. Conclusion: The relationship of income to health varies not only according to the health measure chosen but by age and gender.
