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

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 In the study, twin pairs were withdrawn from the Swedish Twin Registry.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.OCTO-Twin研究（OCTO-Twin Study）旨在探究80岁及以上双生子对之间个体差异的成因，研究覆盖健康与功能能力、认知功能、心理健康状况、人格与个人控制感等多个领域。本研究的双生子对均选自瑞典双生子登记库（Swedish Twin Registry）。首轮调查阶段，双生子需于1913年及之前出生，且双生子双方均同意参与研究。1991-1994年的基线调查中，共纳入351对双生子（149对单卵双生子、202对同性别双卵双生子），受试者平均年龄为83.6岁，女性占比67%。后续针对所有存活且同意参与的双生子开展每两年一次的纵向随访，整个研究历时8年，累计完成5轮数据采集。第二波调查共有235对双生子参与，涉及568名受试者。如需了解变量组与单个变量的更多细节，请参阅NEAR门户（NEAR portal）中关于首轮调查/基线调查及各独立数据集的说明。