Sammanfattning
A compelling literature substantiates that our social worlds have significant and far-reaching
effects on
health and well-being throughout life. Yet, few studies of social factors and their effects on health
have been
embedded within the twin design. Towards this end, we have initiated a new twin study on social
factors and
health which will investigate the genetic and environmental influences on social environments, and
explore
how social environments mediate these influences on physical and mental health. Herein, we
describe the
study sample, response rates and measures. Twins born 1935-1960 were invited to complete a
questionnaire
and these data were supplemented with information on cardiovascular disease and cancer through
linkage to
national health registries. Among the 10655 twins who were contacted, responses were received from
5446
individuals (1989 pairs and 1468 single responders). The subsample of pairs where both twins
responded includes
1004 identical (MZ) pairs and 985 fraternal (DZ) pairs. The overall individual and pairwise response
rates were 51% and 37%, respectively. The average age is 61.54 years, 56.1% of the responders are
female
and 46.1% are identical twins. MZ twins were more likely to participate than DZ twins. Sex and age
effects
were statistically significant for many of the psychosocial measures and for measures of support and
strain
in the social network. There were no differences in the social networks between twins in pairs where
both
twins responded and twins in pairs where only one twin responded.