Assessment of Tea Consumption
Tea consumption was assessed at the baseline survey for all participants and reassessed 2 to 3 years later for more than 91.4% of the participants at the first follow-up survey. Each participant was asked whether she drank tea regularly (at least thrice per week lasting at least 6 months) and at what age she started such habit, followed by questions on the type and amount (dry weight) of tea (tea leaves) consumed during the past year, as well as current status of tea consumption. Those who were former tea drinkers were further asked about the age when they last drank tea regularly.