Jessica L. Seidelman
The current CDC National Healthcare Safety Network method of calculating rates of surgical site infection, or SSI, underestimates the SSI rate in procedures like laminectomies and rectal surgeries that are performed with higher-ranking procedures, researchers found.
Jessica L. Seidelman, MD, MPH, a medical instructor in the division of infectious diseases at Duke University School of Medicine, and colleagues from the Duke Infection Control Outreach Network (DICON) help hospitals submit data to the National Healthcare Safety Network (NHSN).
“In our process of reviewing SSIs, we realized that hospitals were calculating denominators differently and this prompted us to take a deeper look at SSI denominators,” Seidelman explained to Infectious Disease News.
Seidelman and colleagues performed a retrospective analysis of SSI surveillance data from 11 hospitals in DICON from Jan. 1, 2015, to Dec. 31, 2017, including only hospitals where 200 or more primary spinal fusions and 200 or more primary colon surgeries were performed to ensure rates were not affected by low procedure volume.
“We examined SSI rates of laminectomies and rectal procedures using two different denominators: (1) current NHSN definition or (2) only when the rectal or laminectomy procedure was the primary procedure (ie, adjusted SSI rate),” they wrote.
According to the study, infection preventionists identified 87 SSIs associated with 17,247 laminectomies and seven SSIs associated with 740 rectal procedures. After calculating percentages, the researchers found that the NHSN SSI rate and adjusted SSI rate for laminectomies were 0.5 and 0.72, respectively, showing a 30.6% increase. For rectal surgeries, the NHSN and adjusted rates were 0.95 and 2.3 respectively, representing a 58.7% increase.
“The key finding is that the current proposed method for calculating denominators is troublesome in that if you have a surgery that involves both a rectal procedure and a colon procedure, but the infection is attributed to the colon procedure, then this counts toward the colon numerator and denominator, but only the rectal denominator. This potentially leads to misleading SSI rates. If we are not going to count a procedure in the numerator, we should also not count it in the denominator,” Seidelman said. “If we want to have clinicians and hospitals make informed decisions for their patients, then we need to ensure that the data they use to make those decisions are accurate.” – by Caitlyn Stulpin
Disclosure: Seidelman reports no relevant financial disclosures.