Several strengths and limitations should be considered when interpreting the findings. A major feature of this study is that extensive information was obtained on tea consumption and personal habits, as well as diet, lifestyle, and factors relevant to hormonal status. A validated and reliable instrument specifically for Chinese women was used to collect the required information. Test-retest results, conducted in Hangzhou, confirmed the reproducibility of the questionnaire. The intraclass correlation coefficient was 0.83 for tea consumption.