Direct medical costs and length of stay associated with postoperative systemic infectious complications after gynecologic surgery: a propensity score–matched case–control study

Background and aim To quantify the independent impact of postoperative systemic infectious complications (PSIC) on direct medical costs and length of stay (LOS) for patients undergoing gynecologic surgery. Methods This was a retrospective case–control study conducted at a large tertiary healthcare facility in southwestern China. The participants included patients who underwent gynecologic surgery between January 2022 and December 2024. The study included 202 patients with PSIC (case group) and 600 matched patients without PSIC (control group) following 1:3 propensity score matching (PSM). The primary outcomes measured were direct medical costs and LOS, analyzed via a doubly robust estimation framework using Generalized Linear Models (GLMs) to calculate the Average Marginal Effect (AME). Results After matching, baseline covariates were largely balanced, with any residual confounding addressed in downstream models. Total unadjusted direct medical costs were significantly higher in the PSIC group compared with the control group (median ¥31,124.06 vs. ¥20,726.43, p < 0.001), with a median difference of ¥8,127.02. Patients with PSIC had a significantly longer median overall LOS (12 vs. 8 days, p < 0.001) and postoperative LOS (9 vs. 5 days, p < 0.001). Crucially, after doubly robust covariate adjustment, PSIC was found to independently drive an absolute incremental burden of ¥8,960.74 in total medical costs and 4.20 days in prolonged hospitalization (both p < 0.001). Conclusion PSIC following gynecologic surgery independently and substantially increases direct medical costs and prolongs hospitalization. These findings highlight the significant economic burden of these complications and underscore the value of investing in effective infection prevention strategies to optimize resource utilization.