A meta-analysis of education effects on chronic disease: The causal dynamics of the Population Education Transition Curve William C. Smith a, b, * , Emily Anderson a , Daniel Salinas a, c , Renata Horvatek a , David P. Baker a, d a The Pennsylvania State University, EducationTheory and Policy, 300 Rackley Building, University Park, PA 16802, USA b Higher School of Economics, Institute of Education, Moscow 101000, Russia c Organization for Economic Co-operation and Development, Paris 75116, France d The Pennsylvania State University, Population Research Institute, University Park, PA 16802, USA article info Article history: Available online 16 October 2014 Keywords: Chronic disease Education Epidemiological Transition Heterogeneous effects Meta analysis Population Education Transition Curve abstract As the Epidemiological Transition progresses worldwide, chronic diseases account for the majority of deaths in developed countries and a rising proportion in developing countries indicating a new global pattern of mortality and health challenges into the future. Attainment of formal education is widely reported to have a negative gradient with risk factors and onset of chronic disease, yet there has not been a formal assessment of this research. A random-effects meta-analysis finds that across 414 published effects more education significantly reduces the likelihood of chronic disease, except for neoplastic diseases with substantial genetic causes. Some studies, however, report null effects and other research on infectious disease report positive education gradients. Instead of assuming these contradictory results are spurious, it is suggested that they are part of a predictable systemic interaction between multiple mediating effects of education and the Epidemiological Transition stage of the population; and thus represent one case of the Population Education Transition Curve modeling changes in the association between education and health as dependent on population context. © 2014 Elsevier Ltd. All rights reserved. 1. Introduction As the Epidemiological Transition (hereafter, ET) progresses worldwide, chronic diseases account for the majority of deaths in developed countries and a rising proportion in developing coun- tries forming a new global pattern of mortality and health chal- lenges into the future. The ET is the historical change in primary causes of morbidity and mortality from infectious diseases to chronic diseases, progressing through four stages of disease burden: pestilence and famine, receding pandemics, chronic and man-made diseases, and delayed chronic diseases (Yusuf et al., 2001). In developed nations well into advanced stages of the ET, growing obesity, tobacco use, sedentary occupations, and other risk factors coupled with lowering of deadly infectious diseases yield high prevalence of chronic and degenerative diseases (Lopez and Mathers, 2006; Reddy and Yusuf, 1998). At the same time, an un- precedented number of national populations are moving rapidly across ET stages and confronting growing levels of these diseases (Fogel and Grotte, 2011; Omran, 1971, 1983). The pace of the ET is particularly challenging for less-developed countries transitioning from lower to the middle stages as rising prevalence of chronic disease adds to the already substantial disease burden from infec- tious diseases. For example, although incidents of HIV/AIDS and tuberculosis are in decline in Africa, Latin America, and East Asia, growing chronic disease adds to the high disease burden (Amuna and Zotor, 2008; Jamison and Mosley, 1991). The advancing ET is a major worldwide health trend, so understanding the interaction between it and social factors is essential, and chief among these is attainment of formal education. Exposure to formal education is often reported as associated with increased life expectancy, and hence is often referred to as a leading “social vaccine,” meaning a social intervention that pro- vides resources that can protect individuals and elevate the health of populations (Baker et al., 2009; Ubaidullah, 2005). Education as a “social vaccine” is indicated by a negative gradient between educational attainment and disease with the term used in * Corresponding author. The Pennsylvania State University, Education Theory and Policy, 300 Rackley Building, University Park, PA 16802, USA. E-mail addresses: wcs152@psu.edu (W.C. Smith), ewa111@psu.edu (E. Anderson), drs347@psu.edu (D. Salinas), ruh158@psu.edu (R. Horvatek), dpb4@psu.edu (D.P. Baker). Contents lists available at ScienceDirect Social Science & Medicine journal homepage: www.elsevier.com/locate/socscimed http://dx.doi.org/10.1016/j.socscimed.2014.10.027 0277-9536/© 2014 Elsevier Ltd. All rights reserved. Social Science & Medicine 127 (2015) 29e40