Reproducibility of self-reported menopause age at the 24-year follow-up of a population study of women in Göteborg, Sweden

Abstract

Objective: To study the reproducibility of self-reported age at natural menopause, reported by women in their 70s, compared with menopause age reported in the initial postmenopausal period.

Design: A prospective study conducted in Göteborg, Sweden, based on a random sample of the total female population, started in 1968-1969, with follow ups in 1974-1975, 1980-1981, and 1992-1993. A total of 1,009 women born in 1922, 1918, or 1914 (participation rate 90.3%), representative of women of the respective ages in the general population, participated in the initial examination in 1968-1969. Of those women reporting natural menopause some time between 1968 and 1981, 565 women recalled their menopause age in 1992.

Results: The mean interval between the first and second reports was 18.3 years. The mean difference between first-reported and recalled menopause was 0.05 years. When menopause age was recalled in 1992-1993, 55.6% of the women with a natural menopause recalled their age at menopause correctly within 1 year, 22.6% underestimated their menopause age by more than 1 year, and 21.8% overestimated their menopause age by more than 1 year. Women undergoing early menopause (<45 years) tended to overestimate menopause age, whereas women undergoing late menopause (>55 years) tended to underestimate menopause age. These differences could not be explained by age, interval since menopause, smoking, exercise, education, or socioeconomic status.

Conclusions: Menopause ages reported at an interval of almost 20 years showed a significant correlation. However, a regression tendency of the values toward the mean was observed, suggesting that strong correlation at the group level does not imply precision at the extremes.