In the Journals

Inappropriate urine culture practices contribute to overdiagnosis of CAUTIs

Sonali Advani, MBBS, MPH
Sonali Advani

A reliance on “pan-culturing” and inappropriate urine culture practices may be contributing to the overdiagnosis of surveillance catheter-associated UTIs, or CAUTIs, delayed diagnosis of alternative infections and excess Clostridioides difficile infections, study findings showed. Researchers said knowledge gaps among nurses and physicians related to ordering cultures may be contributing factors.

“Physicians and nurses are often influenced by subjective findings — color, odor — and nonspecific symptoms to order urine cultures in catheterized patients. In addition, indiscriminate pan-culturing invariably results in positive urine cultures in catheterized patients due to high incidence of colonization,” Sonali Advani, MBBS, MPH, associate medical director for infection prevention at Yale New Haven Hospital and assistant professor of infectious diseases at Yale School of Medicine, told Infectious Disease News. “These positive urine cultures are often treated inappropriately with antimicrobials, which increases the risk of adverse events. Hence, it is critical to teach general internists, surgeons and nurses about appropriate urine culture practices in catheterized patients.”

To assess practice patterns, Advani and colleagues reviewed charts on CAUTIs between Oct. 1, 2015, and Sept. 30, 2017, and surveyed physicians and nurses between Jan. 11, 2018, and March 9, 2018, about indications for ordering urine cultures in catheterized patients.

Based on the chart review, they identified 184 CAUTIs in 2 years. According to the study, urine cultures were ordered inappropriately in 86% of cases, CAUTI criteria were met by pan-culturing rather than symptom-directed testing in 62% of cases, and patients experienced partial or delayed management of other infections, drug adverse events and C. difficile infections 11% of the time. Additionally, Advani and colleagues found that nurses were more likely than physicians to consider change in appearance (61% vs. 23%) and odor (74% vs. 42%) of urine as indications to order urine cultures, according to the survey.

“Many physicians approach a patient with fever, leukocytosis or hemodynamic instability with a pan-culturing approach instead of symptom-directed evaluation. Though pan-culturing usually provides instant gratification as it may yield positive results, it often has negative consequences over time,” Advani said. “This reliance on pan-culturing and inappropriate culturing practices can lead to [an] increase in diagnosis and treatment of catheter-associated bacteriuria. This may lead to [a] delay in diagnosing other conditions due to anchoring, [an] increase in surveillance CAUTI rates, drug adverse effects and C. difficile infections.

“Our next steps are to use these data to develop a tailored diagnostic stewardship educational curriculum for our medical staff and integrate decision support into the [electronic medical record] to reduce inappropriate urine culture orders. The long-term goal of such an initiative is to reduce diagnosis and treatment of catheter-associated bacteriuria, inappropriate antibiotic use and C. difficile rates.” – by Caitlyn Stulpin

Disclosures: Advani reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.

Sonali Advani, MBBS, MPH
Sonali Advani

A reliance on “pan-culturing” and inappropriate urine culture practices may be contributing to the overdiagnosis of surveillance catheter-associated UTIs, or CAUTIs, delayed diagnosis of alternative infections and excess Clostridioides difficile infections, study findings showed. Researchers said knowledge gaps among nurses and physicians related to ordering cultures may be contributing factors.

“Physicians and nurses are often influenced by subjective findings — color, odor — and nonspecific symptoms to order urine cultures in catheterized patients. In addition, indiscriminate pan-culturing invariably results in positive urine cultures in catheterized patients due to high incidence of colonization,” Sonali Advani, MBBS, MPH, associate medical director for infection prevention at Yale New Haven Hospital and assistant professor of infectious diseases at Yale School of Medicine, told Infectious Disease News. “These positive urine cultures are often treated inappropriately with antimicrobials, which increases the risk of adverse events. Hence, it is critical to teach general internists, surgeons and nurses about appropriate urine culture practices in catheterized patients.”

To assess practice patterns, Advani and colleagues reviewed charts on CAUTIs between Oct. 1, 2015, and Sept. 30, 2017, and surveyed physicians and nurses between Jan. 11, 2018, and March 9, 2018, about indications for ordering urine cultures in catheterized patients.

Based on the chart review, they identified 184 CAUTIs in 2 years. According to the study, urine cultures were ordered inappropriately in 86% of cases, CAUTI criteria were met by pan-culturing rather than symptom-directed testing in 62% of cases, and patients experienced partial or delayed management of other infections, drug adverse events and C. difficile infections 11% of the time. Additionally, Advani and colleagues found that nurses were more likely than physicians to consider change in appearance (61% vs. 23%) and odor (74% vs. 42%) of urine as indications to order urine cultures, according to the survey.

“Many physicians approach a patient with fever, leukocytosis or hemodynamic instability with a pan-culturing approach instead of symptom-directed evaluation. Though pan-culturing usually provides instant gratification as it may yield positive results, it often has negative consequences over time,” Advani said. “This reliance on pan-culturing and inappropriate culturing practices can lead to [an] increase in diagnosis and treatment of catheter-associated bacteriuria. This may lead to [a] delay in diagnosing other conditions due to anchoring, [an] increase in surveillance CAUTI rates, drug adverse effects and C. difficile infections.

“Our next steps are to use these data to develop a tailored diagnostic stewardship educational curriculum for our medical staff and integrate decision support into the [electronic medical record] to reduce inappropriate urine culture orders. The long-term goal of such an initiative is to reduce diagnosis and treatment of catheter-associated bacteriuria, inappropriate antibiotic use and C. difficile rates.” – by Caitlyn Stulpin

Disclosures: Advani reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.