Danish 1905 Cohort Study, 1998 (ICPSR 3960)

Version Date: Aug 22, 2016 View help for published

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


Version V3

This data collection provides information on individuals born in Denmark in 1905 and who were still living in Denmark in 1998. The overall goal of the study was to establish a genetic-epidemiological database to shed light on the aging process among the extremely old. The data focus on their physical and cognitive functioning. Respondents were asked if they had been previously diagnosed with diseases such as diabetes, arthritis, asthma, migraine, cancer, stroke, heart attack, or depression, and if they were experiencing such ailments as cough, body pains, and bone fracture and were taking medication for them. Questions probed respondents' feelings about their health, life, and future. To assess respondents' general health and functioning, they were asked if they needed assistance with toileting, bathing, dressing, and mobility around the house; how often they needed to use the bathroom during the night; and if they used physical aids such as wheelchairs, eyeglasses, crutches, catheters, or diapers. They were also tested for memory and cognition, mobility, vision, speech, hearing, and lung functioning. Information was also elicited on respondents' mental state and awareness, energy level, menopause, frequency of visits with children and family, visits from a nurse, use of home care services, sleeping patterns, smoking and drinking habits, weight gain or loss, exercises, social activities, hobbies, reading habits, television viewing, and recent deaths in the family. Demographic information includes age, education, and marital status.

Christensen, Kaare, and Duke University. Danish 1905 Cohort Study, 1998. Inter-university Consortium for Political and Social Research [distributor], 2016-08-22. https://doi.org/10.3886/ICPSR03960.v3

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Danish National Research Foundation (J.nr.507-102), United States Department of Health and Human Services. National Institutes of Health. National Institute on Aging (PO1AG08761)


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
1905 -- 1998
  1. The data, setup files, and documentation for this collection contain characters with diacritical marks used in the Danish language.

A total of 2,262 persons born in Denmark in 1905. In cases where the individual was cognitively or physically impaired a proxy answered the questions. A home-based two-hour multidimensional interview, including cognitive and physical performance tests and collection of DNA, was carried out by lay interviewers. Population-based registers were used to evaluate how representative the sample was of the population. The participants were located through the Danish Central Office of Civil Registration.

All individuals born in Denmark in 1905, excluding the Faroe Islands and Greenland, and who were still living in Denmark in 1998.


63 percent


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 Duke University. Danish 1905 Cohort Study, 1998. ICPSR03960-v3. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2016-08-22. http://doi.org/10.3886/ICPSR03960.v3

2016-08-22 Respondent ID has been removed to comply with current Danish legislation. ICPSR added English question text to the collection.

2010-06-03 The data are restricted, but the documentation is available for download.

2008-02-11 Minor edits were made to the metadata.

2005-12-06 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:

  • Checked for undocumented or out-of-range codes.

The data are not weighted and contain no weights.


  • The public-use data files in this collection are available for access by the general public. Access does not require affiliation with an ICPSR member institution.

  • One or more files in this data collection have special restrictions. Restricted data files are not available for direct download from the website; click on the Restricted Data button to learn more.

  • The citation of this study may have changed due to the new version control system that has been implemented. Please see version history for more details.