Longitudinal Study of Aging Danish Twins, 1995 Christensen, Kaare Vaupel, James W. activities of daily living aging assisted living assistive devices cognitive devices cognitive functioning disease health status home care mental health older adults physical fitness physical limitations NACDA.V ICPSR.XVII CD-ROM.I The focus of the "Longitudinal Study of Aging Danish Twins (LSADT)" has been on elucidating the causes of variation in survival, health, diseases, loss of abilities, and cognitive functions among the elderly and oldest-old. The LSADT was conducted every two years between 1995 and 2005 and consists of six waves. The study comprises interviews of elderly Danish twins aged 75 years and older (later 70 years and older). At each interview wave, the interview assessment has been based on the interview used in the previous waves, which covers health, physical functioning, cognitive functioning, depression symptomatology, social factors, lifestyle characteristics, and quality of life. The self-report interview assessments have been supplemented with objective indicators of physical strength and agility, behavioral speed, and pulmonary peak-flow. Biological material was also collected from the participants for future DNA analysis. 2009-06-09 survey data 21041 10.3886/ICPSR21041.v1 Denmark Global 1995 ICPSR metadata records are licensed under a Creative Commons Attribution-Noncommercial 3.0 United States License (http://creativecommons.org/licenses/by-nc/3.0/us/).