Abstract
<title>Abstract</title> <p>Background Postoperative pain management remains a significant challenge in health systems worldwide. While standardized pain assessment tools are available, few hospitals have established systematic mechanisms to translate routine assessments into continuous quality improvement. This study aimed to implement and evaluate a closed-loop quality monitoring system using a novel metric—Days with Severe Pain (DSP)—to improve postoperative pain management across a large tertiary hospital. Methods This one-year prospective health services research project was conducted at Peking University Third Hospital, a 2,300-bed tertiary care center in Beijing, China. The DSP indicator—defined as patient-days with a Numerical Rating Scale (NRS) score ≥ 7—was introduced across 10 surgical departments. A standardized pain assessment protocol mandated NRS evaluation on the day of surgery and for three consecutive postoperative days. Monthly DSP ratios (DSP person-days/total inpatient bed-days × 1000‰) were calculated and fed back to departmental leadership through a closed-loop system. Analgesic consumption was standardized using Defined Daily Doses (DDDs) for NSAIDs and oral morphine equivalents for opioids. A total of 733,694 inpatient days were analyzed. Results The annual DSP ratio was 4.657‰. Following implementation, the hospital-wide DSP ratio decreased from 6.93‰ (August 2022) to 2.475‰ (July 2023). The number of patients with severe pain on the day of surgery and postoperative day 1 showed substantial reductions. NSAID consumption increased from 1.81 to 2.23 DDDs/person/day, while opioid consumption decreased from 11.04 mg to 9.41 mg oral morphine equivalents/person/day. High-risk profiles included male gender, patients under 20 years, and those undergoing shoulder, thoracic spine, or hip surgery. Conclusions Implementation of a DSP-centered closed-loop quality monitoring system was associated with meaningful improvements in postoperative pain outcomes and a shift toward multimodal, opioid-sparing analgesia. The DSP metric provides a practical, replicable tool for health systems seeking to strengthen postoperative pain quality monitoring.</p>