Description of women's personality traits and psychological vulnerability prior to choosing hormone replacement therapy

INTRODUCTION: Data suggest that women using hormone replacement therapy (HRT) represent a special subgroup of the general population regarding, for instance, cardiovascular risk factors and education. OBJECTIVE: To analyse if women who choose HRT are characterised a priori by high neuroticism score or by psychological vulnerability. DESIGN: A prospective population-based study was initiated in 1976 with follow-ups in 1981, 1987 and 1996. The population comprises a random sample of 621 women born in 1936 and living in the county of Copenhagen. STUDY METHODS: The analyses are based on data on two sub-cohorts of 268 and 235 women from the large population-based study. These subgroups consist of the women participating in both baselines at 40 and 45 years respectively and at follow-up in 1996. At the age of 40 the women participated in a comprehensive examination, which apart from baseline characteristics included Eysencks personality questionnaire concerning intro/extroversion and neuroticism. At the age of 45, the re-examination of the women included a test for psychological vulnerability. The participants reported whether or not they used HRT at the age of 40, 45, 51 and 60 years. The analyses comprised "never users" of HRT and "future users", defined as women who started HRT subsequent to baseline registration during the observation period. The groups were compared by multivariate statistical methods to adjust for confounding factors. RESULTS: Women with high neuroticism score at the age of 40 were more likely to become users of HRT in the future compared to women with low neuroticism score. At the age of 45, psychologically vulnerable women were more likely to become users of HRT in the future compared to non-vulnerable women. The associations became insignificant when correcting for potential confounders. The study suggests that selection bias among women choosing HRT may also include personality traits.