Methods By purposive sampling, 799 permanent residents were investigated by interview and a self-made questionnaire about their sex, age, ethnic, diet habit, life behavior, drinking water quality.

• 方法统一采用自编的结石病问卷调查表，按目的抽取样本人群，通过面访与自填式问卷调查相结合的方式对恩施地区799名常住人口的性别、年龄、民族、饮食习惯、生活行为、水质等情况进行调查；