Explaining the social patterning of lung function in adulthood at different ages: the roles of childhood precursors, health behaviours and environmental factors

Background \ud Lung function successfully predicts subsequent health. Although lung function is known to decline over age, little is known about changes in association with socioeconomic status (SES) throughout life, and whether explanatory factors for association vary with age or patterns for non smokers. \ud \ud Methods \ud Analyses were based on data on 24 500 participants aged ≥ years from the 1995, 1998 and 2003 Scottish Health Surveys who were invited to provide 1 s forced expiratory volume (FEV1) and forced vital capacity (FVC) lung measurements. Sex-stratified multiple linear regression assessed lung function–SES (occupational social class) associations and attenuation by covariates in three age groups (2003 data (n=7928)). \ud \ud Results The FEV1–SES patterns were clear (p\ud \ud Conclusions We found cross-sectional evidence that SES disparity in lung function increases with age, especially for men. Our findings indicate that early-life factors may predict inequity during younger adulthood, with environmental factors becoming more important at older ages.