Research Suggests Current NHSN CAUTI Definition May Not Reflect Clinical UTI in NSICU Patients

A research poster presented today at the Society for Healthcare Epidemiologists (SHEA) Spring 2017 Conference in St, Louis, MO, suggests that the current National Health Safety Network (NHSN) catheter-associated urinary tract infection (CAUTI) definition may not truly reflect clinical UTI in neurosurgical intensive care unit (NSICU) patients. This is because the current guidelines have eliminated candiduria as a criteria for infection, and have increased “the threshold of bacteriuria.” Because patients in the NSICU commonly have fevers, the use of fever as “a single attribution CAUTI,” likely attributes to capturing, “asymptomatic bacteriuria” in these patients, potentially leading to “over-diagnosis of nosocomial UTIs” in this population.

To test this hypothesis, scientists from the University of Illinois at Chicago College of Medicine and School of Public Health used a retrospective cohort study to assess UTI symptoms indicated in the medical records of “patients admitted to the NSICU in an urban academic medical center from 1/1/2015 to 6/30/2016, with NHSN defined CAUTI.” The presence of a fever, and subsequent resolution of the fever, whether or not patients received antibiotics, and the “underlying neurologic condition” of the patients was also reviewed.

In total, the scientists identified 50 CAUTIs. Of these cases, “23 (46%) [of the CAUTIs] were identified in patients with intracranial hemorrhage, 24 (48%) [of the patients had] other neurologic conditions (stroke, seizure, encephalitis), and 3 (6%) [had] spinal cord injury.”

A total of 41 patients were treated for the infection, with the majority of the patients (78%) only having fever as the identified urinary symptoms. The scientists noted that in this patient population, most of the patients are “unable to report symptoms.” None of the 9 patients who were not treated had UTI symptoms other than a fever.

According to the study results, “the mean days of fever were 4.92 in the treated and 4.86 in the untreated group, and the mean days from culture to resolution of fever were 2.08 and 1.71 (P=.77); 5 treated patients and 2 untreated were discharged prior to resolution of fever.”

Although the population of patients that were assessed was small, the scientists still determined that, “the current NHSN CAUTI definition may still not truly reflect clinical UTI in NSICU patients.” Indeed, because the scientists did not find a difference “in time to resolution of fever” in treated and untreated groups, “a need to better define UTI in neurosurgical patients and improve antimicrobial stewardship,” may be needed.

The recent Agency for Healthcare Research and Quality’s (AHRQ) “National Scorecard on Rates of Hospital-Acquired Conditions” showed that CAUTIs accounted for 15% of healthcare-associated conditions in 2015, a 33% reduction since 2010. A focus on safety has accounted for the reduction in these and other healthcare-associated conditions across the board, and a renewed focus on reducing diagnostic error and practicing appropriate antibiotic stewardship should work to reduce incidence of these infections even further for the next 5-year time period.