Value of Electronic Surveillance for Hospital CAUTIs
By Joseph F. John, Jr., MD, FACP, FIDSA, FSHEA
Associate Chief of Staff for Education, Ralph H. Johnson Veterans Administration Medical Center; Professor of Medicine, Medical University of South Carolina, Charleston.
Dr. John reports no financial relationships relevant to this field of study.
SYNOPSIS: Compared to manual surveillance methods, an electronic surveillance tool for catheter-associated urinary tract infections had a high negative predictive value but a low positive predictive value.
SOURCE: Wald HL, et al. Accuracy of electronic surveillance of catheter-associated urinary tract infection at an Academic Medical Center. Infect Control Hosp Epidemiol 2014;35:685-91.
A group from the University Of Colorado School Of Medicine constructed this study to determine if electronic surveillance for catheter-associated urinary tract infections (CAUTIs) was as good or better than standard surveillance. They used an electronic algorithm to detect UTI in 1695 patients in 2009 and 2010. The patients were included if they had a "high clinical suspicion" of having a CAUTI. The hospital was a 425-bed urban setting. Patients were adults 18 years of age or older. Manual surveillance was the comparator arm. The average age was 57 years and there was a male to female split of 49% to 42% with the remainder unknown. Of the 1695 patients studied, 64 were detected to have CAUTI electronically (15 were true positives) and only 19 were identified by manual surveillance. Electronic surveillance had a high negative predictive value (NPV) but a low positive predictive value (PPV = 23%). There was a 97% agreement between the electronic algorithm and the manual method. On the basis of these predictive values, the authors felt that electronic surveillance would be a good screening tool. The authors suggest that the test characteristics of the electronic algorithm could be improved in order to improve data pulls.
COMMENTARY
The best thing to say about this study is that, while creative, its electronic surveillance could be used in its present form primarily for screening to eliminate negative cases, i.e. its high NPV. This conclusion is somewhat disappointing but electronic surveillance is in its infancy so that the test characteristics when improved may raise the PPV and the tool could be a stand along.
In the meantime, manual surveillance has a wisdom that electronic surveillance cannot approach in documenting true infections. That does not mean that we should not try to continue to use innovative software to help us in this era of mega-data. This article used a Structured Query Language code in Microsoft Access to apply an algorithm that ends in either a CAUTI or an asymptomatic catheter-associated infection. To result in a CAUTI the patient needs to have symptoms and that is the challenging rub for the software to figure out. If there are no symptoms but a positive blood culture the diagnosis is considered at least a level of CAUTI. If there are no symptoms and the blood culture is negative, the urine culture positive for less than 2 organisms at a count of 100,000/cc, then there is then there is not a CAUT, but a CAASB, a catheter-associated asymptomatic bacteriuriaa. While all this process through the algorithm sounds complex—and it is—the use to Infection Control will be a final software that should be easy to apply.
Keep eyes peeled for use of algorithms in software that detects common hospital-acquired infections. For the time being, let us hope this electronic detection of CAUTI can be refined and demonstrate more sensitivity.
