Longitudinal Study of Aging Danish Twins, 1995 (ICPSR 21041)

Version Date: Jun 9, 2009 View help for published

Principal Investigator(s): View help for Principal Investigator(s)
Kaare Christensen, University of Southern Denmark. Institute of Public Health; James W. Vaupel, Duke University


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The focus of the "Longitudinal Study of Aging Danish Twins (LSADT)" was 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 is comprised of interviews of elderly Danish twins aged 75 years and older (later 70 years and older). At each interview wave, the interview assessment was 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 were 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.

Christensen, Kaare, and Vaupel, James W. Longitudinal Study of Aging Danish Twins, 1995. Inter-university Consortium for Political and Social Research [distributor], 2009-06-09. https://doi.org/10.3886/ICPSR21041.v1

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United States Department of Health and Human Services. National Institutes of Health. National Institute on Aging (Grant # P01AG08761), University of Southern Denmark

The data are restricted from general dissemination. Users interested in obtaining these data must complete a Restricted Data Use Agreement form and specify the reasons for the request. Researchers can download this form as a Portable Document Format (PDF) file from the download page associated with this dataset. Completed forms with original signature(s) should be emailed to icpsr-nacda@umich.edu.

Inter-university Consortium for Political and Social Research

1995-02 -- 1995-04
1995-02 -- 1995-04

The LSADT used a cohort sequential design. The sampling for all waves of LSADT is described in M. McGue and K. Christensen. "Social Activity and Healthy Aging: A Study of Aging Danish Twins." Twin Research and Human Genetics 10,2 (2007), 255-266.

All twins aged 75 years and older born in Denmark and still residing in Denmark, not including the Faroe Islands and Greenland.

Physical functioning: The self-reported assessment of physical functioning is based on an instrument that was developed and previously validated in Denmark (Avlund et al, 1995). It has been used essentially unchanged throughout all waves of LSADT.

Cognitive functioning: The cognitive battery includes the Mini Mental State Examination (MMSE, Folstein et al, 1995) and five brief cognitive tests selected to be sensitive to age-related changes (McGue and Christensen, 2002).

Depression symptomatology: The assessment is based on an adaptation of the depression section of the Cambridge Mental Disorders of the Elderly Examination (CAMDEX, Roth et al, 1986; Johnson et al, 2002).

Social activity: The Social Activity scale was not administered in LSADT until 1997.



2018-02-15 The citation of this study may have changed due to the new version control system that has been implemented. The previous citation was:
  • Christensen, Kaare, and James W. Vaupel. Longitudinal Study of Aging Danish Twins, 1995. ICPSR21041-v1. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2009-06-09. http://doi.org/10.3886/ICPSR21041.v1

2009-06-04 ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:

  • Performed consistency checks.
  • Standardized missing values.
  • Checked for undocumented or out-of-range codes.

No weights have been used



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