As could be expected, participants who completed the personality measure at follow-up were those who in 1981 were younger (35 vs. 54 years old; p < .01) and more educated (12.5 vs. 9.7 years of education; p < .01), as compared to those who did not complete the personality assessment (because of mortality, sample loss, or subject refusal). There were no significant differences in the proportion of males and females or ethnic groups (Fisher's exact test: p > .05).
