1. Institute of Chronic Disease; Liaoning Provincial Center for Disease Control and Prevention; Shenyang China
2. Benxi Municipal Center for Disease Control and Prevention; Benxi China
3. Dandong Municipal Center for Disease Control and Prevention; Dandong China
4. Shenyang Municipal Center for Disease Control and Prevention; Shenyang China
5. Anshan Municipal Center for Disease Control and Prevention; Anshan China
6. Dalian Medical University; Dalian China