Aging, Disablement, and Dying: Using Time-as-Process and Time-as-Resources Metrics to Chart Late-Life Change

Abstract

Time is a vehicle that can be used to represent aging-related processes and to index the amount of aging-related resources or burdens individuals have accumulated. Using data on cognitive (memory) performance from two Swedish studies of the elderly (OCTO and OCTO-TWIN), the authors illustrate how time-as-process and time-as-resources/burdens time metrics can be articulated and incorporated within a growth-curve modeling framework. Results highlight the possibilities for representing the contributions of primary, secondary, and tertiary aspects of aging to late-life changes in cognitive and other domains of functioning.

ACKNOWLEDGMENT

The authors gratefully acknowledge grant funds provided by the National Institute on Aging RC1 AG035645, R21 AG032379, and R21 AG004132, the Center for Population Health and Aging at Penn State University (NIH/NIA Grant R03 AG028471-01) to combine the data sets, The European Union project contract no. QLK6-CT-2001-02283 and the Research Board in the County Council of Jönköping, and the Research Council in the Southeast of Sweden for their funding of the OCTO study, NIA grant AG-08861 for the funding of the OCTO-Twin study. The authors would also like to extend their gratitude to Stig Berg, who was an instrumental leader in the collection of the Swedish data sets, and whose research career contributed significantly to the current study. Special thanks also to Gerald McClearn from Penn State University, Boo Johansson from the University of Göteborg, and the research teams at the Institute for Gerontology in the College of Health Sciences at Jönköping University in Sweden, the Center for Developmental and Health Genetics at the Pennsylvania State University, and the Division of Genetic Epidemiology at the Karolinska Institute in Stockholm, Sweden for their design and collection of the original data.