A Longitudinal Twin Study of Gender Differences in Health Behavior and Health Among Elderly is a unique study of unlike sex twins that derives from the Swedish Twin Registry.
The sample of unlike sex twins makes it possible to use the brother and sisters as matched pairs and reduce the problem of different selection into old age among men and women. The study contains several phases.
A postal survey was sent in 1995 and received answers from 605 pairs unlike sex twins. A first in person testing of 249 pairs born 1916 to 1925 was carried out 1995-1997. This group of twins have been followed-up twice, in 1999-2001 and 2003-2005. A final survey was carried out 2008.
The main interest of the study has been health in health behaviors in old age, as the name indicate. Questions about subjective health, medicine consumption and behaviors and attitudes related to health, perceived ADL capacity, personality and social networks, formal and informal care etc. are available. Further, measures of grip-strength, vital capacity, blood pressure, a number of exercises related to muscle strength and balance, and cognitive functions are available. Blood values and genotyping are also available.
Data from Gender is included in several larger research consortium, such as NEAR (National E-infrastructure for Aging Research), IGEMS: The Consortium on Interplay of Genes and Environment across Multiple Studies, and The CODATwins Project: the COllaborative project of Development of Anthropometrical measures in Twins.
The study has been supported by The MacArthur Foundation, USA, Axel och Margaret Ax:son Johnson stiftelse till stöd för allmännyttiga ändamål, FNR through SFR, FAS (currently FORTE), and Konung Gustav V:s minnesfond.