Background: Inequalities in health are a major public-health concern. A greater understanding is needed on the relative importance of different causes. We investigated the contribution of risk factors identified at different life stages to inequalities in self-rated health.
Methods: We used data from 5606 men and 5799 women in the 1958 British birth cohort followed-up to age 33 years, on health behaviour, education, adolescent health, family structure and social support, work characteristics, and material circumstances. We assessed the contribution of different factors to social-class differences in self-rated health by adjustment of odds ratios (classes IV and V vs I and II).
Findings: Odds ratios of poor-rated health at age 33 were 3.15 for men and 2.30 for women, which decreased to 2.06 and 1.34, respectively, after adjustment for previously identified factors from birth to early adulthood. Adjustment for adult work characteristics, material circumstances, and health behaviour between ages 23 years and 33 years further decreased the odds ratios to 1.64 (men) and 1.11 (women). Most factors contributed to the reduction in odds ratios, although adolescent socioemotional adjustment, class at birth, educational qualifications, and psychosocial job strain were especially important. Additional key factors for men were adult smoking and job insecurity, and for women, housing during childhood, adult income, and age at first child.
Interpretation: There was no single cause of health inequality at age 33 years. Explanations spanned from early life to young adulthood. Policy implications include reduction of social differences in material circumstances and of differences in individual skills and resources acquired in early life.