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The causal effects of education on health outcomes in the UK Biobank

Abstract

Educated people are generally healthier, have fewer comorbidities and live longer than people with less education1,2,3. Much of the evidence about the effects of education comes from observational studies, which can be affected by residual confounding. Natural experiments, such as laws that increase the minimum school leaving age, are a potentially more robust source of evidence about the causal effects of education. Previous studies have exploited this natural experiment using population-level administrative data to investigate mortality, and surveys to investigate the effect on morbidity1, 2,4. Here, we add to the evidence using data from a large sample from the UK Biobank5. We exploit the raising of the minimum school leaving age in the UK in September 1972 as a natural experiment6. We used a regression discontinuity design to investigate the causal effects of remaining in school. We found consistent evidence that remaining in school causally reduced the risk of diabetes and mortality in all specifications.

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Fig. 1: Years of full-time education by quarter of birth.
Fig. 2: The effect of the reform on each outcome estimated using the difference-in-difference approach accounting for age effects.
Fig. 3: The effect of the 1972 reform in Clark and Royer2 and UK Biobank.

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Acknowledgements

We thank the Social Science Genetic Association Consortium for providing the coefficients from the educational attainment genome-wide association study, and G. Hemani, L. Paternoster, D. Carslake, J. Bowden, L. Zuccolo, E. Stergiakouli and E. Sanderson for helpful comments on an earlier draft. All mistakes remain our own. The Medical Research Council (MRC) and the University of Bristol fund the MRC Integrative Epidemiology Unit (MC_UU_12013/1 and MC_UU_12013/9). N.M.D. is supported by the Economics and Social Research Council (ESRC) via a Future Research Leaders grant (ES/N000757/1). The research described in this paper was specifically funded by a grant from the ESRC for Transformative Social Science. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. This work was carried out using the computational facilities of the Advanced Computing Research Centre (www.bris.ac.uk/acrc/) and the Research Data Storage Facility of the University of Bristol (www.bris.ac.uk/acrc/storage/). This research was conducted using the UK Biobank Resource.

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N.M.D. obtained funding for this study, analysed and cleaned the data, interpreted results, and wrote and revised the manuscript. M.D. interpreted the results and wrote and revised the manuscript. G.J.v.d.B. interpreted the results and wrote and revised the manuscript. G.D.S. obtained funding for this study, interpreted results and wrote and revised the manuscript. F.W. obtained funding for this study, interpreted results and wrote and revised the manuscript.

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Correspondence to Neil M. Davies.

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Davies, N.M., Dickson, M., Davey Smith, G. et al. The causal effects of education on health outcomes in the UK Biobank. Nat Hum Behav 2, 117–125 (2018). https://doi.org/10.1038/s41562-017-0279-y

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