Stability of the type A structured interview and related questionnaires in a 10-year follow-up of an adult cohort of twins.

Associations between initial and 10-year follow-up assessment of the Type A behavior pattern (TABP) were examined in a sample of adult male twins using a broad range of instruments. When assessment is made by the Structured Interview and limited to the dichotomous Types A and B rating, 67% of the subjects received the same rating on both occasions. Spearman rank correlations between repeated self-report measures of TABP ranged from .55 to .70. Overall the stability among the self-report measures was greater than between the self-reports and the Structured Interview. Utilizing the twin design the relationship of genetic and environmental factors to tracking of TABP was examined and compared between monozygotic and dizygotic twin pairs. The implication of these results to the TABP construct is discussed.