Origin of Variances in the Oldest-Old: Octogenarian Twins
The study aimed to investigate the etiology of individual differences among twin-pairs age 80 and older, on a range of domains including health and functional capacity, cognitive functioning, psychological well-being, personality and personal control.
- Start Year
- 1991
- End Year
- 2002
Visit OCTO-Twin
| Investigators | Contacts |
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Design
- Study design
- Cohort
- Follow Up
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Participants were assessed up to 5 times at 2-year intervals providing up to 8 years of follow-up
- Supplementary Information
Marker Paper
[McClearn, G. E., Johansson, B., Berg, S., Pedersen, N. L., Ahern, F., Petrill, S. A., et al. (1997). Substantial genetic influence on cognitive abilities in twins 80 or more years old. Science, 276, 1560-1563.]
PUBMED 9171059
Recruitment
- Sources of Recruitment
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- Families
Number of participants
- Number of participants
- 702
- Number of participants with biosamples
- 552
Access
Availability of data and biosamples
| Possible Access to Data | |
| Possible Access to Biosamples | |
| Other |
Timeline
OCTO-Twin - Population
Twin pairs were drawn from the Swedish population-based Twin Registry. At the first wave the twins had to be born 1913 or earlier and both partners in the pair had to accept participation. At the first wave 351 twin pairs (149 MZ and 202 like-sex DZ pairs) were investigated (average age 83.57 years; 67% of the sample were female). The two-year longitudinal follow-ups were conducted on all twins alive who agreed to participate, irrespective of twin status. The participation in the 2nd Wave was 235 pairs (568 individuals), in the 3rd wave 144 pairs (430 individuals), in the 4th wave 4 86 pairs (315 individuals), and at the last occasion (wave 5) 43 pairs (222 individuals participated. The initial OCTO-Twin sample was found to be similar to a representative sample of non-twins aged 80 and older (Simmons et al., 1997). Linkages are continuously performed to the Twin Registry/Census register and to the death register for vital status.
Selection Criteria
- Minimum age
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79
- Maximum age
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98
- Newborns
- Twins
- Countries
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- Sweden
- Territory
- Ethnic Origin
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- Health Status
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- Other criteria
- Supplementary Information
Recruitment
- Sources of recruitment
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- Specific population
- Specific Population
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- Other specific population : The Swedish population-based Twin Registry
Number of participants
- Number of participants
- 702
- Number of participants with biosamples
- 552
- Supplementary Information
-
351 twin pairs, including 149 identical or monozygotic (MZ) pairs, and 202 same-sex fraternal or dizygotic (DZ) twin pairs
Data Collection Events
| # | Name | Description | Start | End |
|---|---|---|---|---|
| 0 |
OCTO-Twin - wave 1
|
Baseline |
1991-02 | 1994-03 |
| 1 |
OCTO-Twin - wave 2
|
First follow-up of participant. The number of tested individuals and pairs were 568 and 235 respectively. |
1993-05 | 1996-05 |
| 2 |
OCTO-Twin - wave 3
|
Second follow-up of participant. The number of tested individuals and pairs were 430 and 144 respectively. |
1995-04 | 1998-05 |
| 3 |
OCTO-Twin - wave 4
|
Third follow-up of participant. The number of tested individuals and pairs were 315 and 86 respectively. |
1997-04 | 2000-05 |
| 4 |
OCTO-Twin - wave 5
|
Fourth follow-up of participant. The number of tested individuals and pairs were 222 and 43 respectively. |
1999-12 | 2002-03 |