Origin of Variances in the Oldest-Old: Octogenarian Twins (OCTO-Twin) Wave 2

SND-ID: 2021-195-2.

Is part of collection at SND: NEAR - National E-Infrastructure for Aging Research in Sweden

Access to data via


Creator/Principal investigator(s)

Linda Hassing - University of Gothenburg, Department of Psychology orcid

Research principal

University of Gothenburg - Department of Psychology rorId


The OCTO-Twin Study aims 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. In the study, twin pairs were withdrawn from the Swedish Twin Registry.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 baseline in 1991-94, 351 twin pairs (149 monozygotic and 202 like-sex dizygotic pairs) were investigated (mean age: 83.6 years and 67% were female). The two-year longitudinal follow-ups were conducted on all twins who were alive and agreed to participate. Data have been collected at five waves over a total of eight years.

In wave 2, 235 twin pairs participated, with a total of 568 individuals.
Refer to the description of wave 1/the base line and the individual datasets in the NEAR portal for more details on variable groups and individual variables.

Data contains personal data


Sensitive personal data


Type of personal data

Pseudonymised data related to mental and physical health, as well as socio-demographics and social relationships

Code key exists



Method and outcome

Unit of analysis


Twin pairs from the Swedish Twin Registry who were born 1913 or earlier and were at the age of 80 years at baseline.

Study design

Observational study

Cohort study

Cohort study: Prospective

Description of study design

Longitudinal study

Time period(s) investigated

1991 – 2002



Number of individuals/objects


Data format / data structure

Data collection
  • Mode of collection: Measurements and tests
  • Description of the mode of collection: The participants were examined in their home settings by registered nurses. The participants also answered a number of self-administered surveys.
  • Time period(s) for data collection: 1993-05 – 1996-05
  • Data collector: University of Gothenburg
  • Sample size: 568
  • Source of the data: Registers/Records/Accounts: Medical/Clinical, Registers/Records/Accounts
Geographic coverage

Geographic spread

Geographic location: Sweden

Administrative information

Responsible department/unit

Department of Psychology

Ethics Review

Other - Ref. S-005011-50

Approval of Assurance to Comply with 45 CFR 46. Public Health Service, National Institutes of Health, USA. Office for Protection from Research Risks. July 20, 1999. Accepted by the ethical committee of the Karolinska Institute


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Cadar, D., Piccinin, A. M., Hofer, S. M., Johansson, B., & Muniz-Terrera, G. (2016). Education, occupational class, and cognitive decline in preclinical dementia. In GeroPsych: The Journal of Gerontopsychology and Geriatric Psychiatry (Vol. 29, Issue 1, pp. 5–15).
DOI: https://doi.org/10.1024/1662-9647/a000138

Berg, A. I. (2008). Life satisfaction in late life: Markers and predictors of level and change among 80+ year olds [Doctoral thesis]. Department of Psychology, University of Gothenburg.
Handle: https://hdl.handle.net/2077/17873
ISBN: 9789162876012

Wikby, A., Ferguson, G. F., Forsey, R., Thompson, J., Strindhall, J., Löfgren, S., Nilsson, B.-O., Ernerudh, J., Pawelec, G., & Johansson, B. (2005). An immune risk phenotype, cognitive impairment and survival in very late life: The impact of alostatic load in Swedish Octo- and Nongenarian humans. In The Journals of Gerontology: Series A, Volume 60, Issue 5 (pp. 556–565).
DOI: https://doi.org/10.1093/gerona/60.5.556

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.
DOI: https://doi.org/10.1126/science.276.5318.1560

Hassing, L. (2020). Gender Differences in the Association Between Leisure Activity in Adulthood and Cognitive Function in Old Age: A Prospective Longitudinal Population-Based Study. In The journals of gerontology. Series B, Psychological sciences and social sciences (Vol. 75, Issue 1, pp. 11-20).
DOI: https://doi.org/10.1093/geronb/gbx170
SwePub: oai:gup.ub.gu.se/266566

Johansson, B., Johansson, B., McClearn, G., & Pedersen, N. (2003). Health, biobehavioral functioning, and personality in the oldest-old: The Swedish OCTO-Twin Study. Presented at the 56th Annual Scientific Meeting of the Gerontological Society of America, San Diego. In GERONTOLOGIST (Vol. 43, Special Issue 1, p. 507).

Yoneda, T., Rush, J., Berg, A. I., Johansson, B., & Piccinin, A. (2017). Trajectories of Personality Traits Preceding Dementia Diagnosis. In The journals of gerontology. Series B, Psychological sciences and social sciences (Vol. 72, Issue 6, pp. 922–931).
DOI: https://doi.org/10.1093/geronb/gbw006
SwePub: oai:gup.ub.gu.se/243248

Hofer, S. M., Johansson, B., Berg, S., Pedersen, N. L., & McClearn, G. E. (2001). Changes in Cognitive Functioning in the Oldest-Old Twins : The Octo-Twin Study. Presented at the 54th Annual Scientific Meeting of the Gerontological Society of America, Chicago. In GERONTOLOGIST (Vol. 41, Special Issue 1, p. ?).

Nilsson, B.-O., Ernerudh, J., Johansson, B., Evring, P.-E., Löfgren, S., Ferguson, F. G., & Wikby, A. (2003). Morbidity does not influence the T-cell immune risk phenotype in the elderly : Findings in the Swedish NONA Immune Study using sample selection protocols. In Mechanisms of Ageing and Development (Vol. 124, Issue 4, pp. 469–476). https://doi.org/10.1016/S0047-6374(03)00024-1
DOI: https://doi.org/10.1016/S0047-6374(03)00024-1
URN: urn:nbn:se:liu:diva-26438
SwePub: oai:DiVA.org:liu-26438

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