Background. Cognitive function and intelligence quotient (IQ) have been related with adult mortality in some but not all studies. IQ was not related to coronary heart disease or stroke after the age of 651 and childhood IQ was not related to mortality in women2. Adjustment for socioeconomic circumstances partly explains this association3. Furthermore, childhood cognitive ability could determine school performance and thus, influence later socioeconomic position. Research in this area is limited and ASLPAC offers a unique opportunity to investigate whether cognitive function is already socially patterned at a young age.

Objective. The objective of this project is to investigate whether cognitive function in childhood is socially distributed, using different aspects of cognitive function and different measures of socioeconomic position.

Main variables for this project. We will need variables measuring cognitive function (e.g. McArthur Communicative Development Inventory at 20 months, Pre-School Language Scales (PLS-3), McCarthy Scales of Children's Abilities at 36 months, etc.), family background details, and the primary carer's verbal functioning (Mill Hill Vocabulary Scale), are and individual socioeconomic position indicators, socio demographic characteristics and school characteristics.

Statistical analysis. We will assess the social patterning of cognitive function in the children, with particular attention to using different indicators of life course socioeconomic position to describe this distribution. We will conduct multiple regression analysis. Sensitivity analyses will be carried out to explore the degree to which misclassification of both exposures and confounders could influence the observed effect estimates.

References.

1. Hart CL, Taylor MD, Smith GD, et al. Childhood IQ and cardiovascular disease in adulthood: prospective observational study linking the Scottish Mental Survey 1932 and the Midspan studies. Soc Sci Med 2004;59:2131-8.

2. Kuh D, Richards M, Hardy R, Butterworth S, Wadsworth ME. Childhood cognitive ability and deaths up until middle age: a post-war birth cohort study. Int J Epidemiol 2004;33:408-13.

3. Huisman M, Kunst AE, Mackenbach JP. Intelligence and socioeconomic inequalities in health. Lancet 2005;366:807-8.