An international concortium led by Janet Stocks, UCL and funded initiallly by Asthma UK, has produced reference equations for spirmoetry from childhood through to adult life (www.growing lungs.org). This project is an extension of this work utilising large collections of lung function data from cohort and cross-sectional studies to refine the current reference equations. ALSPAC has greater than 7000 measurements fo spirmoetry in 8 year olds and a further 4000 from 15 year olds that will be a valuable addition to the resource and wil be appropriately credited in publicatiosn arising from this work.

Data required are spirometry measurements form Focus@8: FEV1, FVC and mid expiratory flows (FEF 25-75) and child's sex, height and weight on day of measurement. No other identifying information will be sent.