Many cohort studies have mechanisms for sharing data with external researchers on a collaborative basis, but relatively few have arrangements for open access to the data without any need for collaboration, and even fewer have been established from the outset with the intention of making the entire resource available to the global research community. The development of open access arrangements for data from cohort studies is an important step in maximising their impact with respect to scientific publications, policy making, and understanding of health and disease. Examples of resources whose impact has been enhanced in this way include the UK 1958 birth cohort study [13] and the Australian 45 and Up cohort study [14].
