Long schooling was associated with a reduced risk of all-cause mortality in adults
A systematic review and meta-analysis by US scientists found that the number of years of education was statistically associated with a reduced risk of all-cause mortality in adults. As reported in The Lancet Public Health, the average reduction in the risk of death is 1.9 percent for each year of education, with the largest effect observed in the 18-49 age group: there, each additional year of education reduced the risk of all-cause mortality by 2.9 percent.
According to the researchers, all-cause mortality rates are declining worldwide, and this decline is expected to continue. This trend is attributed to improvements in a wide range of determinants of health, such as improved access to and quality of health care, technological advances, poverty reduction, access to clean water, labor rights, and access to education.
The positive relationship between increased access to schooling and improved social health indicators is well recognized. Education is thought to influence individual health through psychosocial, economic, and cognitive influences. For example, studies have shown that long schooling is associated with delayed loss of cognitive function in the familial form of Alzheimer's disease. The importance of education for both children and adults is recognized by the World Health Organization, which advocates for accessible primary and secondary education for children and higher education for adults. However, with hitherto unequal access to education worldwide, no one has systematically assessed the magnitude of the impact of education on adult mortality.
Therefore, a collaboration of scientists from the US-based Institute for Health Metrics and Evaluation quantified the reduction in the risk of all-cause mortality as a function of the number of years of education. To do so, they conducted a systematic review and meta-analysis of 603 scientific papers from 59 countries, totaling 10,355 observations.
The initial analysis showed that, compared with no education, completion of six grades was associated with a 13.1 percent reduction in the risk of all-cause mortality when adjusted for age, sex, and marital status. After 12 years of education, the reduction in mortality risk was 24.5 percent after 12 years of education and 34.3 percent after 18 years of education. On average, each additional year of education led to an average 1.9 percent reduction in mortality risk. Researchers found no evidence of non-linearity or attenuation of the effect of education on mortality risk across the full range of exposures.
That said, the researchers clearly observed different effects of education on mortality risk across age groups. For example, for those aged 18-49 years, each additional year of education reduced the risk of all-cause mortality by 2.9 percent; for adults older than 70 years, the reduction reached only 0.8 percent. Gender and country sociodemographic index did not significantly affect the association between the number of years of education and the risk of all-cause mortality.
Although the researchers found significant study heterogeneity (p < 0.0001), this study is the first global quantification of the effect of educational attainment on the risk of all-cause mortality in adults. The results of the study bring together previously disparate knowledge about the positive effects of education on the social health of populations.