1. Department of Clinical Pharmacy & Pharmacy Administration, West China Pharmacy School, Sichuan University, No. 17 Section 3 Renmin Nanlu, Chengdu, Sichuan 610041, China
2. Department of Acupuncture & Chinese Medicine, Canadian College of Acupuncture and Oriental Medicine, 551 Chatham Street, Victoria, BC, Canada V8T 1E1
3. Center for Health Research North West, Kaiser Permanente, 5025 Southeast 28th Avenue, Portland, OR 97202, USA
4. Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada L8S 4L8