1. Innovation Center of Nursing Research, Nursing Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, P. R. China
2. West China School of Nursing, Sichuan University, Chengdu 610041, Sichuan Province, P. R. China
3. School of Economic Mathematics, Southwestern University of Finance and Economics, Chengdu 611130, Sichuan Province, P. R. China
4. School of Business Administration, Southwestern University of Finance and Economics, Chengdu 611130, Sichuan Province, P. R. China
5. West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, P. R. China
6. School of Management and Economics, University of Electronic Science and Technology of China, Chengdu 611731, Sichuan Province, P. R. China