The reproducibility of self-reported age at menarche: The Tromsø Study

Abstract

BackgroundPrevious studies of the reproducibility of self-reported age at menarche have been limited because of small study samples, short follow-up and the limited age span of the women included.MethodsThe present study assessed the reproducibility of age at menarche in 6731 women with a wide variation of age when giving the information about age at menarche. The women reported age at menarche in a self-administered questionnaire, both in 1986–1987 and 1994–1995. They were all residents of Tromsø, Norway, and aged 25–73 in 1994–1995. In order to investigate the agreement between self-reported age at menarche at the two points in time, Pearson’s correlation coefficient was applied to assess the linear correlation between the reported menarcheal age at the two occasions. Analyses were stratified for age. A Bland-Altman plot was produced and limits of agreement computed.ResultsWe found a high correlation and a strong agreement between self-reported age at menarche in 1986–1987 and 1994–1995. The overall Pearson’s correlation coefficient was 0.84 and was not attenuated by increasing age of the women. The Bland-Altman plot showed a strong agreement in self-reported age at menarche. The mean difference between self-reported age at menarche was 0.01 years with limits of agreement −1.52 to 1.54.ConclusionWe found high reproducibility of self-reported age at menarche. The mean menarcheal age in the two surveys was identical (13.2 years) with 95% of the women reporting the same age at menarche or with a difference of 1 year. Only 0.7% of the women reported age at menarche with a difference of more than 2 years in 1986–1987 and 1994–1995.

Incidence of Breast Cancer in the Life Span Study of Atomic Bomb Survivors: 1958–2009

“…Therefore, while it reduces our ability to detect modification of radiation risks, we do not believe that having incomplete data resulted in biased risk estimates. Reproductive history was self-reported, although such information is typically reported reliably (47,48) and recall bias is unlikely. Another possible limitation is lack of data on expression of estrogen (ER), progesterone (PR) and human epidermal growth factor receptors (HER2) that define several biologically distinct subtypes of breast cancer (49)(50)(51).…”

Ultrasound assessment of pubertal breast development in girls: intra- and interobserver agreement

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Age at menarche in Seveso daughters exposed in utero to 2,3,7,8-tetrachlorodibenzo-p-dioxin

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