Intelligence in youth and all-cause-mortality: systematic review with meta-analysis

Calvin, C.M., Deary, I.J., Fenton, C. , Roberts, B.A., Der, G. , Leckenby, N. and Batty, G.D. (2011) Intelligence in youth and all-cause-mortality: systematic review with meta-analysis. International Journal of Epidemiology, 40(3), pp. 626-644. (doi:10.1093/ije/dyq190)

Full text not currently available from Enlighten.

Abstract

Background: A number of prospective cohort studies have examined the association between intelligence in childhood or youth and life expectancy in adulthood; however, the effect size of this association is yet to be quantified and previous reviews require updating.

Methods: The systematic review included an electronic search of EMBASE, MEDLINE and PSYCHINFO databases. This yielded 16 unrelated studies that met inclusion criteria, comprising 22 453 deaths among 1 107 022 participants. Heterogeneity was assessed, and fixed effects models were applied to the aggregate data. Publication bias was evaluated, and sensitivity analyses were conducted.

Results: A 1-standard deviation (SD) advantage in cognitive test scores was associated with a 24% (95% confidence interval 23–25) lower risk of death, during a 17- to 69-year follow-up. There was little evidence of publication bias (Egger’s intercept = 0.10, P = 0.81), and the intelligence–mortality association was similar for men and women. Adjustment for childhood socio-economic status (SES) in the nine studies containing these data had almost no impact on this relationship, suggesting that this is not a confounder of the intelligence–mortality association. Controlling for adult SES in five studies and for education in six studies attenuated the intelligence–mortality hazard ratios by 34 and 54%, respectively.

Conclusions: Future investigations should address the extent to which attenuation of the intelligence–mortality link by adult SES indicators is due to mediation, over-adjustment and/or confounding. The explanation(s) for association between higher early-life intelligence and lower risk of adult mortality require further elucidation.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Fenton, Ms Candida and Der, Mr Geoffrey and Batty, Dr G
Authors: Calvin, C.M., Deary, I.J., Fenton, C., Roberts, B.A., Der, G., Leckenby, N., and Batty, G.D.
Subjects:R Medicine > R Medicine (General)
College/School:College of Medical Veterinary and Life Sciences > Institute of Health and Wellbeing > MRC/CSO Unit
College of Medical Veterinary and Life Sciences > Institute of Health and Wellbeing > Public Health
Journal Name:International Journal of Epidemiology
Publisher:Oxford University Press
ISSN:0300-5771
ISSN (Online):1464-3685
Published Online:29 October 2010

University Staff: Request a correction | Enlighten Editors: Update this record