Abstract
To the Editor:
Surgical site infection (SSI) is one of the most commonly reported healthcare–associated infections (HAIs), accounting for approximately 20% of all HAIs. 1 How to implement effective monitoring and prevention is the major concern for global infection preventionists (IPs) and surgeons. According to the data from the National Quality Control Center for Hospital Infection Management of China, the SSI rate in tertiary hospitals has remained below 1% for several years, with the clean incision rate even lower than 0.1%. In contrast, the global incidence of SSI is reported to be 2.5% (95% CI: 1.6–3.7). 2 Why the SSI rate in China is significantly lower than that in the United States (via the CDC’s National Healthcare Safety Network, NHSN) or other countries has been one of the major issues that have long perplexed Chinese IPs. The significant differences in reported SSI rates between the United States and China can be attributed to several key factors.
Differences in Calculation Method
The NHSN of the United States recommends the use of the standardized infection ratio (SIR) to report infection rates. A limitation of using pooled mean rates is that they do not account for differences in risk among populations, which can undermine comparability across time and between different entities. The adjustment of SIR helps account for variations in patient populations and surgical complexities. For instance, logistic regression models are often used to calculate the probability of SSI, establishing a relationship between the log-odds and the probability of infection. 3 However, the National Medical Institution Infection Surveillance System of China mainly relies on retrospective reporting data and cross-sectional data and does not standardize according to risks. Such differences in calculation methods have led to the noncomparability between SSI and SIR.
Difference in Denominator
The United States defines the denominator for SSI rates as the total number of procedures performed within specific operative categories that are actively monitored and reported through the NHSN. This means that only those surgical procedures selected for surveillance in a facility’s monthly reporting plan (MRP) are included in the denominator for SSI rate calculations. Procedures not included in the MRP are not counted in the SSI rate denominator, even if an SSI occurs following such a procedure. This approach ensures that the SSI rate reflects the infection risk associated with the specific procedures that a facility has chosen to monitor. In contrast, the denominator for calculating the SSI rate in China includes all types of surgeries. This broad surveillance method may lead to less precise monitoring of SSI rates, as it dilutes the impact of higher-risk procedures.
Difference in Numerator
Surveillance systems and methodologies
Operates under standardized, evidence-based protocols with mandatory reporting for certain high-risk procedures. Surveillance is typically conducted by trained infection preventionists, ensuring consistent data collection across participating hospitals. For example, patient surveys by mail or telephone can be used as one of the methods for Surveillance. 4
Surveillance practices in China vary significantly across hospitals and regions. Notably, more than half of SSI cases occur after patients are discharged, which presents a significant challenge for monitoring and follow-up care. In the developed eastern and southern regions of China, medical institutions have required shorter hospital stays and a faster bed turnover rate. However, there are few IPs responsible for patient follow-up. In rural areas where resources are relatively scarce, affecting the effective monitoring of SSI. 5
Non-sharing of patient information
In the United States, different medical institutions can share patients’ inpatient and surgical information. For instance, SSI was identified because of a patient’s readmission to a facility other than where the procedure was performed, marked as “RO,” but it would also be reported as SSI. 6 In China, patient information is not universally shared between different medical institutions, which can hinder effective follow-up and post-discharge surveillance for SSIs. When a patient undergoes a procedure in Hospital A, Hospital A does not follow up on patients’ post-operative infections. Because of the issue of proximity treatment or trust crisis, it is possible that debridement treatment for SSI is performed in Hospital B. However, at this time, Hospital B will determine the post-operative infection of the patient as community-acquired SSI.
In conclusion, it is recommended that China establish a nationwide network for SSI surveillance, utilizing unified criteria supported by informatics. Emphasizing tailored prevention measures informed by local data and ongoing observation is crucial. In addition, further research into the impact of SSIs should be prioritized to enhance prevention strategies. 7
Footnotes
Acknowledgments
The authors would like to express their gratitude to Professor Jeanette J. Rainey, Director of the Division of Global Health Protection, Centers for Disease Control and Prevention of the United States, for her guidance and assistance in our research.
Author Disclosure Statement
No competing financial interests exist.
Funding Information
This work was supported by the National Institute of Hospital Administration, Medical artificial intelligence clinical application research project (YLXX24AID001).