The Cohorts and Longitudinal Studies Enhancement Resources (CLOSER) project aims to provide and document a range of key variables that have been harmonised across multiple UK birth cohorts to encourage cross-cohort research on longitudinal data sets and permit compatrisons across as well as within cohort studies. Due to the restrictions on using and holding ALSPAC data (particularly data obtained through linkage) it is our aim to derive standardised measures from education, income and social class variables that are harmonised with derived data from the other cohorts. These variables, once derived, will be deposited back to ALSPAC with accompanying documentation and will not specifically be used for research outputs at this point other than documenting summary statistics. As such, there are no exposure, outcome or confounding variables to outline.

Documentation will be held by CLOSER and made readily available to researchers in an attempt to provide a suitable search platform for commonly requested variables and therefore encourage cross-cohort analysis of data.