Post-endoscopic infections occur more commonly, and infection rates vary markedly among facilities, according to a study published in Gut. More than 15 million colonoscopies are performed each year in the US.

"The observed post-endoscopic infection rates at some ambulatory surgical centers (ASCs) are over 100 times higher than their expected rates that account for patient severity and procedure complexity," noted Peiqi Wang, MD, a postdoctoral research fellow from the Division of Gastroenterology and Hepatology, Johns Hopkins University, and colleagues.

More than 15 million colonoscopies and 7 million esophagogastroduodenoscopies (EGDs) are performed each year in the United States, with more than half of the procedures now performed in ASCs.

Although studies have examined rates of colonoscopy-associated complications such as bleeding and perforation, none have evaluated the rates of associated infectious complications, Wang and colleagues note.

To close that knowledge gap, the authors examined the rates of infection after colonoscopy and EGD performed in ASCs and compare them with the rates of infection after screening mammography, prostate cancer screening, bronchoscopy, and cystoscopy. They also examined variation in the rates of post-endoscopic infection among the different centers.

Using data from ASC, emergency department (ED), and inpatient claims from 6 states in 2014, Wang and colleagues identified 462,068 screening colonoscopies performed at 1157 ASCs, 914,140 screening colonoscopies performed at 1202 ASCs, and 873,138 EGDs performed at 1212 ASCs.

In the comparator groups, they identified 647,212 screening mammographies performed at 338 ASCs, 26,428 prostate cancer screenings at 209 ASCs, 30,116 bronchoscopies at 665 ASCs, and 68,432 cystoscopies at 912 ASCs.

At 7 days post-endoscopy, there were 1.1 infection-related ED visits per 1000 nonscreening colonoscopies, 1.6 per 1000 nonscreening colonoscopies, and 3.0 per 1000 EGDs.

Variation by Treatment Facility

The rates of infections at 7 days post-endoscopy varied markedly among ASCs, ranging from 0 to 115 per 1000 procedures for screening colonoscopy, 0 to 132 for nonscreening colonoscopy, and 0 to 62 for EGD.

The researchers also identified several patient-, procedure-, and facility-related factors associated with post-endoscopic infection. These include younger or older patient age, black or Native American race, male sex, a history of hospitalization or endoscopy in the last 30 days, a concurrence of 2 endoscopic procedures, ASCs with low annual procedure volume, and nonfreestanding ASCs.

The results of this study are especially important for ASCs not only because they lack infection control units but also because patients are unlikely to return to these centers for care for their post-endoscopic infections.

"These factors greatly impede the identification of infection-related complications at ASCs and can result in undetected infectious outbreaks that can profoundly harm many patients," Wang and colleagues conclude.

Although they suggest that quality reporting might prevent ASC-specific post-endoscopic infections, the authors emphasize that clinicians should inform patients of the infectious risk associated with all endoscopic procedures.