The impact of gender on moderate-to-severe pain during the postoperative recovery period in patients undergoing elective thoracic surgery: a single-center retrospective cohort study

Background: Gender differences in pain perception and analgesic response have become increasingly recognized; however, their impact on moderate-to-severe postoperative pain following elective thoracic surgery remains poorly characterized. Objective: To investigate the influence of gender on moderate-to-severe pain during the postoperative recovery period in patients undergoing elective thoracic surgery. Study Design: A single-center retrospective cohort study. Setting: Operating room of a large university-affiliated tertiary hospital. Methods: Adult patients who underwent elective thoracic surgery were enrolled and stratified into two groups by gender. The primary outcome was the incidence of moderate-to-severe pain during the postoperative recovery period. Secondary outcomes included the incidence and scores of moderate pain and severe pain during recovery, postoperative hospital length of stay (LOS), time to first ambulation, and time to chest tube removal. Following propensity score matching (PSM), univariate logistic regression was performed to assess the association between gender and the incidence of moderate-to-severe postoperative recovery pain. Sensitivity analyses were conducted using three distinct models. Subgroup analyses via multivariate logistic regression were carried out to validate the effect of gender on moderate-to-severe recovery pain across different patient populations. A multivariate logistic regression model was employed to identify risk factors for moderate-to-severe recovery pain, and a receiver operating characteristic (ROC) curve was generated. The Baron & Kenny causal analysis approach was used to construct a mediation model for examining the mediating effect of moderate-to-severe recovery pain. Results: A total of 12,075 patients were initially enrolled, with 2,974 patients included in the final analysis after PSM. The incidence of moderate-to-severe pain during the recovery period was significantly higher in males than in females (4.18% vs. 2.53%, p = 0.01). Specifically, the incidence of moderate pain was higher in males compared to females (3.0% vs. 1.5%, p = 0.014), and the Visual Analog Scale (VAS) score for moderate pain was also significantly higher in males (6 [6, 6] vs. 6 [5, 6], p = 0.004). Additionally, males had significantly longer time to chest tube removal and postoperative LOS than females. Subgroup analyses revealed significant gender differences in the incidence of moderate-to-severe pain among patients with no smoking history, no drinking history, younger age (≤ 65 years), American Society of Anesthesiologists (ASA) physical status classification I-II, and those who underwent laparoscopic surgery. The mediating effect of moderate-to-severe pain in the post-anesthesia care unit (PACU) on postoperative LOS and time to chest tube removal was not statistically significant. The area under the curve (AUC) of the logistic regression-based model was 0.88 (95% confidence interval: 0.80-0.95), indicating that gender had high predictive value for moderate-to-severe pain during the recovery period. Limitations: This study is a single-center retrospective analysis, which is inherently susceptible to selection bias and information bias. Conclusion: Among patients undergoing elective thoracic surgery, compared with males, females have a lower incidence of moderate-to-severe pain during the postoperative recovery period, as well as shorter time to chest tube removal and postoperative LOS. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.