The purpose of the work described in this application is to archive the Swedish Adoption/Twin Study of Aging (SATSA) data collected by NIH Grant No. R01AG10175 with the Inter-University Consortium for Political and Social Research (ICPSR) and in collaboration with the National Archive of Computerized Data on Aging (NACDA) at the University of Michigan. Data archiving serves the purpose of enabling other investigators to make use of this resource, both by itself and in multi-study efforts across different studies with similar information. Increasing the availability of these data may facilitat additional harmonization activities, as highlighted in NIA harmonization workshops in Los Angeles (May 2011) and Bethesda (November 2011). The archiving activities described here entail converting the complex questionnaire and in-person testing data into controlled access public use files with user-friendly formats that facilitate data use. SATSA includes multiple longitudinal waves of assessment of cognitive functioning, physical health, and well-being, via both self-report questionnaire (Q) and in-person testing (IPT). Previously, the first 4 questionnaire waves and the first 3 waves of in-person testing have been archived at the ICPSR. The data archiving proposed here adds 2 more Q waves and 2 more IPT waves, and would make available data from 2174 participants with up to 6 waves of questionnaire data and from a subset of 859 individuals aged 50 and older with up to 5 in-person assessments. Whereas 3 waves of assessment are adequate to support modeling linear changes with age, 5 waves of assessment provide sufficient data for modeling more complex trajectories of change with age: accelerating decline and multiple change points. Assessment in multiple domains allows for testing cross-domain relationships. Importantly, adding 2 more waves of IPT and Q data to the data archive increases the proportion of the sample that has participated in at least 3 waves of measurement. The activities described in this application include formatting datasets and creating documentation consistent with ICPSR standards. Direct identifiers are already removed;in the course of preparing data files for archiving, we will further de-identify the data o protect the confidentiality of participants. The completed SATSA data archive thus has a potential to address many secondary analysis questions concerning psychological and social processes in aging and the behavior genetics of aging.
Data archiving is encouraged by NIH as a way to make data as widely and freely available as possible to the research community while safeguarding the confidentiality of participants. Those participating in the original study were motivated to contribute to knowledge about the aging process and sources of cognitive decline in older adults. Archiving serves the aspirations of those participants and the interests of public health by permitting the fullest possible use of the information that was collected. The research questions that can be addressed by those using the data archive are of intense public interest, namely, discovering potentially modifiable lifestyle factors and health behaviors that improve the probability for maintaining functioning across domains in old age.