1233. Surveillance Quality Correlates with SSI Rates in Prosthetic Hip and Knee Surgery: A Call to Action to Adjust Reporting of SSI rates

BACKGROUND: Surgical site infections (SSIs) are rather infrequent following knee and hip surgery, but can have profound consequences for the patient. SSI data from a large network of Swiss hospitals has routinely been collected in a nationwide SSI surveillance system since 2009. The aim of the study was to investigate whether SSI rates are correlated with the quality of surveillance. METHODS: We calculated the weighted mean NNIS adjusted infection rates for hip and knee surgeries for the years in which audits occurred in each hospital. The 50-point score per audit is an amalgamation of quantitative and qualitative information from both structured interviews and a random selection of reviewed patient records, including (amongst others) an evaluation of completeness of medical documentation, follow-up, data quality, and training. RESULTS: The analysis included 30’696 knee and hip surgeries from 92 hospitals (excluding those institutions with <50 procedures in the audit year), with median infection rate 1% (IQR [1–2%]) and median audit score 35 (IQR [32–39]). The Figure plots the NNIS adjusted infection rate against audit score along with the linear fit (solid red) and 95% confidence intervals (gray). There is large variability in rates and scores, with a noticeable increasing trend (P = 0.01). Using the median of both metrics to divide the plot into 4 quadrants, those hospitals in the lower left quadrant have both low infection rates and low audit scores (predominantly private hospitals), whereas those in the upper right quadrant have both higher SSI rates and audit scores (mostly public hospitals). Those in the lower right quadrant represent the ideal situation with both low rates and high-quality surveillance. CONCLUSION: In this national surveillance of nosocomial SSI hip and knee infections, there was a wide range of SSI rates and surveillance quality, with discernible clustering of hospital types. Those hospitals with low infection rate correlated with low-quality audit scores. Surveillance systems without routine evaluation of validity may underestimate the true incidence of SSIs. Audit quality should be taken into account when interpreting SSI rates, perhaps by infection rates for those hospitals with lower audit scores. [Image: see text] DISCLOSURES: All authors: No reported disclosures.