Parental education and lung function of children in the PATY study.

Studies of the relationships between low socio-economic status and impaired lung function were conducted mainly in Western European countries and North America. East-West differences remain unexplored. Associations between parental education and lung function were explored using data on 24,010 school-children from eight cross-sectional studies conducted in North America, Western and Eastern Europe. Parental education was defined as low and high using country-specific classifications. Country-specific estimates of effects of low parental education on volume and flow parameters were obtained using linear and logistic regression, controlling for early life and other individual risk factors. Meta-regressions were used for assessment of heterogeneity between country-specific estimates. The association between low parental education and lung function was not consistent across the countries, but showed a more pronounced inverse gradient in the Western countries. The most consistent decrease associated with low parental education was found for peak expiratory flow (PEF), ranging from -2.80 to -1.14%, with statistically significant associations in five out of eight countries. The mean odds ratio for low PEF (<75% of predicted) was 1.34 (95% CI 1.06-1.70) after all adjustments. Although social gradients were attenuated after adjusting for known risk factors, these risk factors could not completely explain the social gradient in lung function.