infection control & hospital epidemiology
november 2015, vol. 36, no. 11
commentary
CAUTI Surveillance: Opportunity or Opportunity Cost? Daniel J. Livorsi, MD, MSc;1,3 Eli N. Perencevich, MD, MS2,3 (See the article by Tedja et al7 on pages 1330–1334.) Increasingly, payers, legislators, regulators, consumer groups, and the general public have become interested in the prevention of hospital-acquired infections (HAIs). Most states have mandated public reporting of HAIs, and some financial reimbursements are now linked to how effectively hospitals prevent infections. For example, HAI prevention is a central part of the Centers for Medicare and Medicaid (CMS) Hospital-Acquired Condition (HAC) Reduction Program. In this program, 65% of a hospital’s total HAC score is based on the observedto-predicted number of central line-associated bloodstream infections (CLABSIs) and catheter-associated urinary tract infections (CAUTIs). When a hospital falls in the highest quartile of HAC scores, a stiff financial penalty is imposed: CMS reduces the hospital’s reimbursements by 1%. Evaluating hospital quality, however, is fraught with difficulties. A good HAI metric should be objective, reflect a clear episode of patient harm, and be preventable through the implementation of evidence-based practices. The question at hand is whether these standards are met by the National Healthcare Safety Network (NHSN) surveillance definition for CAUTI as part of the HAC Reduction Program. Whether a NHSN-defined CAUTI represents an episode of patient harm is debatable. Because the surveillance definition does not coincide with physician practices, each CAUTI does not necessarily represent a preventable infection or antibiotic prescription.1 Furthermore, because the criteria used to define a CAUTI are nonspecific, it is unclear what exactly the metric is measuring. To meet the current CAUTI definition, a patient must meet 3 simple criteria: (1) the presence of a Foley catheter for >2 days; (2) a urine culture growing ≥105 colony-forming units per milliliter (CFU/mL) of bacteria; and (3) signs or symptoms suggestive of a urinary tract infection (UTI). This final criterion has been met by a temperature >38°C in 79.7% of cases reported to the NHSN.2 The nonspecificity of the NHSN criteria is highlighted in the intensive care unit (ICU), where the simultaneous occurrence of these 3 findings is common. Foley utilization in the ICU ranges from 48% to 76% depending on the type of unit, while fever,
including those secondary to noninfectious causes, occurs in 26%–70% of patients.3,4 In addition, many patients have a positive urine culture even before they reach the hospital. Asymptomatic bacteriuria is reported in up to 19% of community-dwelling elderly, 27% of diabetics, and 50% of elderly within long-term care.5 The risk of acquiring bacteriuria increases by 3%–7% for every day a Foley remains in place, but the constellation of these 3 findings—Foley, fever, and bacteriuria —does not necessarily indicate an infection of the urinary tract. As a clinician, a CAUTI is often a diagnosis of exclusion. The Infectious Diseases Society of America CAUTI guidelines emphasize the importance of ruling out an alternate cause of a catheterized patient’s fever before attributing the fever to bacteriuria.6 In contrast, the NHSN definition assigns all fevers to the urinary tract as long as the other CAUTI criteria are met. Although surveillance definitions will never entirely coincide with clinical infections, the wide gap between the 2 classifications for CAUTI warrants investigation. To quantify this gap, Tedja et al7 reviewed all NHSN-defined CAUTIs that occurred in their medical center’s ICU during 2012–2013. In 97% of patients with a NHSN-CAUTI, the urine culture had been ordered because the patient had a fever. Upon further chart review, the investigators noted that 68% of these febrile cases had a potential alternate explanation for the fever. In fact, 68% may be an underestimate because a standardized, exhaustive search for the cause of fever was not routinely performed. Thus, the investigators were unable to state the definitive cause of each case of fever(s). Nevertheless, since experts agree that catheter-associated bacteriuria and candiduria are rarely the cause of fever in ICU patients,8 it is probable that many, if not most, of these febrile “CAUTI” patients did not have a true urinary tract infection. As the authors acknowledge, their findings may be limited now that the NHSN-CAUTI definition has again been revised. Based on these 2015 revisions, urine cultures with
november 2015, vol. 36, no. 11
commentary
CAUTI Surveillance: Opportunity or Opportunity Cost? Daniel J. Livorsi, MD, MSc;1,3 Eli N. Perencevich, MD, MS2,3 (See the article by Tedja et al7 on pages 1330–1334.) Increasingly, payers, legislators, regulators, consumer groups, and the general public have become interested in the prevention of hospital-acquired infections (HAIs). Most states have mandated public reporting of HAIs, and some financial reimbursements are now linked to how effectively hospitals prevent infections. For example, HAI prevention is a central part of the Centers for Medicare and Medicaid (CMS) Hospital-Acquired Condition (HAC) Reduction Program. In this program, 65% of a hospital’s total HAC score is based on the observedto-predicted number of central line-associated bloodstream infections (CLABSIs) and catheter-associated urinary tract infections (CAUTIs). When a hospital falls in the highest quartile of HAC scores, a stiff financial penalty is imposed: CMS reduces the hospital’s reimbursements by 1%. Evaluating hospital quality, however, is fraught with difficulties. A good HAI metric should be objective, reflect a clear episode of patient harm, and be preventable through the implementation of evidence-based practices. The question at hand is whether these standards are met by the National Healthcare Safety Network (NHSN) surveillance definition for CAUTI as part of the HAC Reduction Program. Whether a NHSN-defined CAUTI represents an episode of patient harm is debatable. Because the surveillance definition does not coincide with physician practices, each CAUTI does not necessarily represent a preventable infection or antibiotic prescription.1 Furthermore, because the criteria used to define a CAUTI are nonspecific, it is unclear what exactly the metric is measuring. To meet the current CAUTI definition, a patient must meet 3 simple criteria: (1) the presence of a Foley catheter for >2 days; (2) a urine culture growing ≥105 colony-forming units per milliliter (CFU/mL) of bacteria; and (3) signs or symptoms suggestive of a urinary tract infection (UTI). This final criterion has been met by a temperature >38°C in 79.7% of cases reported to the NHSN.2 The nonspecificity of the NHSN criteria is highlighted in the intensive care unit (ICU), where the simultaneous occurrence of these 3 findings is common. Foley utilization in the ICU ranges from 48% to 76% depending on the type of unit, while fever,
including those secondary to noninfectious causes, occurs in 26%–70% of patients.3,4 In addition, many patients have a positive urine culture even before they reach the hospital. Asymptomatic bacteriuria is reported in up to 19% of community-dwelling elderly, 27% of diabetics, and 50% of elderly within long-term care.5 The risk of acquiring bacteriuria increases by 3%–7% for every day a Foley remains in place, but the constellation of these 3 findings—Foley, fever, and bacteriuria —does not necessarily indicate an infection of the urinary tract. As a clinician, a CAUTI is often a diagnosis of exclusion. The Infectious Diseases Society of America CAUTI guidelines emphasize the importance of ruling out an alternate cause of a catheterized patient’s fever before attributing the fever to bacteriuria.6 In contrast, the NHSN definition assigns all fevers to the urinary tract as long as the other CAUTI criteria are met. Although surveillance definitions will never entirely coincide with clinical infections, the wide gap between the 2 classifications for CAUTI warrants investigation. To quantify this gap, Tedja et al7 reviewed all NHSN-defined CAUTIs that occurred in their medical center’s ICU during 2012–2013. In 97% of patients with a NHSN-CAUTI, the urine culture had been ordered because the patient had a fever. Upon further chart review, the investigators noted that 68% of these febrile cases had a potential alternate explanation for the fever. In fact, 68% may be an underestimate because a standardized, exhaustive search for the cause of fever was not routinely performed. Thus, the investigators were unable to state the definitive cause of each case of fever(s). Nevertheless, since experts agree that catheter-associated bacteriuria and candiduria are rarely the cause of fever in ICU patients,8 it is probable that many, if not most, of these febrile “CAUTI” patients did not have a true urinary tract infection. As the authors acknowledge, their findings may be limited now that the NHSN-CAUTI definition has again been revised. Based on these 2015 revisions, urine cultures with
