The relationship between educational level and mortality. The Reykjavik Study

Objectives. Epidemiological studies have indicated an association between s ocioeconomic factors and health. It has not been clearly established whethe r this association is wholly or partly independent of classical risk factor s. Our objective was to estimate the relationship between educational level and coronary artery disease (CAD), mortality and all-cause mortality. The Reykjavik Study involving 18 912 participants followed-up 4-30 years provid es an ideal opportunity to address this question. Design and subjects, The participants were aged 33-81 years and living in t he Reykjavik area. They were divided into four groups according to educatio n. The standard risk factors were assessed on entry and mortality, and caus e of death registered during follow-up. Multiple Cox regression analysis wa s applied to assess the relationship between age at examination, year of ex amination, educational level and mortality. Results. The all-cause mortality and CAD mortality was significantly relate d to education, even after adjustment for classical risk factors. For men, 14% (95% CI: 2-24) reduction was found in CAD mortality for those having hi gh school education relative to elementary school. The figures for junior c ollege and university education were 17%, (95% CI: 1-31) and 38% (95% CI: 2 1-32), respectively. These figures were only sightly lower when major CAD r isk factors were controlled for and still significant. Similar figures were found for all-cause mortality. For women 34%, (95% CI: 18-48) reduction wa s found in CAD mortality for high school education and 55% (95% CI: 22-74) for junior college, but too few had university education for reliable resul ts. The figures were lower for all-cause mortality, but significant. The fi gures were reduced when major CAD risk factors were controlled for, but sti ll significant. Conclusion. Education is a strong protective factor both for all-cause and CAD mortality. Only a small part of this effect can be explained through co nventional risk factors.