No evidence for effects of family environment on asthma: A retrospective study of Norwegian twins

摘要

The risk of developing asthma contingent upon the co-twins' history of asthma was analyzed in a population-based study of 5,864 Norwegian twins. A primary aim was to assess the significance of shared environment for the development of asthma from infancy through age 25. Retrospective re- ports were collected when the twins were 18 to 25 yr of age. The risk of developing asthma, contin- gent upon the co-twin's history of asthma, was estimated using survival analyses, and genetic and environmental sources of variation in liability for asthma were analyzed with structural equation models.