Intelligence in childhood and chronic widespread pain in middle age: the National Child Development Survey.
Gale CR., Deary IJ., Cooper C., Batty GD.
Psychological factors are thought to play a part in the aetiology of chronic widespread pain. We investigated the relationship between intelligence in childhood and risk of chronic widespread pain in adulthood in 6902 men and women from the National Child Development Survey (1958 British Birth Cohort). Participants took a test of general cognitive ability at age 11 years; and chronic widespread pain, defined according to the American College of Rheumatology criteria, was assessed at age 45 years. Risk ratios (RRs) and 95% confidence intervals (CIs) were estimated using log-binomial regression, adjusting for sex and potential confounding or mediating factors. Risk of chronic widespread pain, defined according to the American College of Rheumatology criteria, rose in a stepwise fashion as intelligence fell (P for linear trend <0.0001). In sex-adjusted analyses, for an SD lower intelligence quotient, the RR of chronic widespread pain was 1.26 (95% CI 1.17-1.35). In multivariate backwards stepwise regression, lower childhood intelligence remained as an independent predictor of chronic widespread pain (RR 1.10; 95% CI 1.01-1.19), along with social class, educational attainment, body mass index, smoking status, and psychological distress. Part of the effect of lower childhood intelligence on risk of chronic widespread pain in midlife was significantly mediated through greater body mass index and more disadvantaged socioeconomic position. Men and women with higher intelligence in childhood are less likely as adults to report chronic widespread pain.