A development dataset specific to adult Chinese patients undergoing orthopaedic surgery was obtained from PAIN OUT (1985 qualified patients of 2244).  Outcomes were assessed using the International Pain Outcomes Questionnaire (IPO-Q), which comprises key patient-level outcomes of perioperative pain management, including pain experience and perceptions of care. 
PAIN OUT
A more recent validation dataset obeying the same conditions was obtained from the Chinese Anaesthesia Shared-database Platform (1004 qualified patients of 1032). 
Chinese Anaesthesia Shared-database Platform
Outcomes were assessed using the International Pain Outcomes Questionnaire (IPO-Q), which comprises key patient-level outcomes of perioperative pain management, including pain experience and perceptions of care. 
International Pain Outcomes Questionnaire (IPO-Q)