Abstract
Orthopaedic inpatients have distinct clinical traits. This study aimed to quantify the burden of nosocomial infections (NIs) on orthopaedic patients. A nested case-control study (2022-2024) at the China National Orthopaedic Medical Center compared orthopaedic inpatients with and without NIs and matched cases and controls 1:3 to evaluate the burden of NIs. A national economic burden analysis was subsequently conducted under various scenarios. Among 120,764 eligible patients, 338 (0.28%) developed NIs. A total of 321 cases were matched with 916 controls. The economic and temporal burdens of NIs are US$2,100 and 5 days per case respectively. Haematologic NIs had the highest additional cost (US$4,295) and the second longest extended stay (9 days). In terms of initial hospitalisations and readmissions, surgical site infections extended hospital stays by 20 days and increased costs by US$4,881. The top three diagnosis-related groups (DRGs) with high burdens are ZC11, ZJ15, and IE21 for costs and ZJ15, IE21, and IB19 for duration. In the mixed-region scenario, orthopaedic specialty hospitals nationwide incur US$5.23 million in direct medical costs annually because of NIs. These findings indicate that NIs significantly affect orthopaedic patients both individually and nationally, necessitating focused prevention and control for high-burden DRGs and specific infections.