Study Finds Infection-Related Complications after Colonoscopy, Endoscopy Higher Than Previously Thought in the US

Researchers from Johns Hopkins Medicine have found that infections after endoscopic procedures are more common than previously thought. Furthermore, the results indicated all endoscopic procedures held a greater risk of postprocedure infection than screening mammography; however, they were still lower risk than bronchoscopy and cystoscopy.

According to the study results, the rates of a patient having a postendoscopic infection (per 1000 procedures) within 7 days of having the procedure were 3.0 for osophagogastroduodenoscopies (OGDs), 1.6 for nonscreening colonoscopy, and 1.1 for screening colonoscopy. The risk of postprocedure infection for screening mammography was found to be 0.6 (per 1,000 procedures), 15.6 for bronchoscopy and 4.4 for cystoscopy (P<.0001).

Susan Hutfless, PhD, SM, assistant professor of medicine, and lead author on the study, remarked on these findings in a press release, stating, “Though patients are routinely told that common endoscopic procedures are safe, we found that postendoscopic infections are more common than we thought, and that they vary widely from one ambulatory surgery center (ASC) facility to another.”

For the study, investigators tracked unplanned emergency department (ED) visits and hospital stays of patients who had undergone a colonoscopy or OGD procedure performed at an ASC within 7 to 30 days. The team used statewide ASC, ED, and inpatient claims data from 6 states in 2014. Infections were examined by site involved (gastrointestinal, respiratory, genitourinary and central nervous systems as well as septicemia and infectious endocarditis), as well as by organism (E coli, Klebsiella pneumoniae, Clostridium difficile, Pseudomonas, Staphylococci, Streptococci, gram-negative, and anaerobic bacteria).

In 2014, a total of 462,068 screening colonoscopies were performed at 1,157 ASCs, 914,140 non-screening colonoscopies were performed at 1,202 ASCs, and 873,138 OGDs were performed at 1.212 ASCs.

Of those procedures, 1.1 of every 1,000 screening colonoscopies resulted in a 7-day infection related unplanned visit vs 1.6 of every 1,000 non-screening colonoscopy and 3.0 of every 1,000 OGD procedures. Thirty-day infection-related unplanned visits were 4.0 per 1,000 screening colonoscopies, 5.4 for every 1,000 non-screening colonoscopy, and 10.8 for every 1,000 OGD procedures.

Those patients who had been hospitalized prior to receiving the procedure were at greater risk of infection. As indicated in the press release, “almost 45 in 1,000 patients who’d been hospitalized within 30 days prior to a screening colonoscopy visited a hospital with an infection within a month. Within those same parameters, the rate of infection-related hospitalization for EGDs was more than 59 patients per 1,000.”

According to Dr. Hutfless, health officials previously believed that postendoscopic infection rates were about 1 in 1 million.

The number of patients undergoing screening mammography and prostate cancer screening for the same time period were used as non-endoscopic comparator groups, with screening mammography used as the primary comparator because they are more likely to occur in ASCs than prostate cancer screenings. According to the authors, “these screening tests provided the opportunity to estimate the background rate of infection that would occur stochastically after a visit at an ASC, which was helpful for understanding the net influence of colonoscopy and OGD on infection outcomes. [They] then compared the rates with bronchoscopy and cystoscopy…[as] these procedures are common endoscopic procedures that involve sedation and often occur in the same ASC as gastrointestinal endoscopic procedures.”

Based on these comparators, the investigators found that rates of 7-day infection-related unplanned visits were 2-fold to 5-fold higher than the rate for screening mammography (0.6) and 2-fold higher for prostate screening (1.6).

The study investigators state that “the infection rates in this study can serve as a baseline estimate of the current burden of postendoscopic infection-related complications.” In addition, although the study is not without limitations, these findings, “can also serve as the scientific foundation for decision makers to identify if targeted interventions are needed in endoscopy units at ASCs to prevent the incidence of postendoscopic infections, similar to the interventions targeted to surgical and intensive care units to prevent the health care-associated infections in those settings.”