Annals for Hospitalists Inpatient Notes - Trends in Rates of Catheter-Associated Bloodstream InfectionZeroing In on Zero or Just Fake News?

Reports suggest that rates of central lineassociated bloodstream infection (CLABSI) have steadily decreased over the past 2 decades. For example, the Centers for Disease Control and Prevention (CDC) reported a 58% decline in CLABSI rates from 2001 to 2009 across intensive care units (1); a decrease was noted between 2004 and 2013 in hospitals participating in the Michigan Keystone Project (2); and the National and State HealthcareAssociated Infections Progress Report has shown that CLABSI rates declined by 50% between 2008 and 2014. Although encouraging, a fundamental question remains: Why have we been so successful at reducing CLABSI but not other health careassociated infections, such as surgical site or catheter-associated urinary tract infections? Are the newsworthy reductions in CLABSI rates credible? The Case for Novel Technology and Strategies In the past 2 decades, several novel technologies, such as antibiotic- and antiseptic-impregnated catheters, alcohol-containing chlorhexidine, and chlorhexidine-impregnated dressings, were introduced to prevent CLABSI. In addition, bundled strategies and an emphasis on education and training for personnel who insert and maintain catheters diffused widely. There is little doubt that these interventions have contributed to the reduction in CLABSI rates (3). The Importance of Public Policy The precise effect of public policy on CLABSI is unclear. In 2008, the Centers for Medicare & Medicaid Services instituted financial penalties for hospitals with higher-than-expected rates. At least 2 studies have reviewed the effects of such penalties: 1 suggested no effect on infection, whereas the other reported a decline. Whether financial penalties have actually changed practice at the bedside remains unknown. However, one fear is that such policies may dissuade clinicians from ordering blood cultures in patients with central venous catheters. Less testing could result in lower detection, which would improve hospital performance without changing patient outcomes. In addition to the nonreimbursement policies adopted in 2008, several states have instituted public reporting of hospital-acquired infection rates. In 2004, only 4 states had such a requirement, but by 2016, 38 states and the District of Columbia required public reporting. Again, it is difficult to ascertain how these policies affect care at the bedside, but by design, they pressure hospitals to reduce CLABSI to zero. That economic incentives to influence practice can lead to unintended consequences is well-known. In the case of CLABSI, financial pressure could lead to changes in the way that it is defined or detected. Accounting Methods The determination of CLABSI rates is inherently dependent on the definition of CLABSI and methods used for case-finding. Changes in either of these influence the interpretation of data over time. The National Healthcare Safety Network definition of CLABSI requires the presence of a laboratory-confirmed bloodstream infection in a patient with a central venous catheter and no identifiable alternative source of bacteremia. The last criterion is especially subjective. Policies tying public reporting to nonpayment could influence hospitals to adopt an intense search for alternate sources of bacteremia. Of note, such relentless searches did not occur in the absence of financial consequences. Thus, while CLABSI rates over the past 2 decades may have been overestimated, it is plausible that current accounting strategies may underestimate these rates, especially if some are attributed to other sources of bacteremia. Even with rigorous application of the National Healthcare Safety Network definition, interrater reliability can be suboptimum (4). To prevent misclassification of bacteremia caused by oral or gastrointestinal organisms in patients with neutropenia or graft-versus-host disease, in 2013 the CDC added another category for laboratory-confirmed bloodstream infections: mucosal barrier injury. This new category is intended to improve comparability of CLABSI rates by specifically classifying infections caused by certain pathogens as non-CLABSIs. The addition of mucosal barrier injury was a welcome change, especially for institutions caring for large numbers of patients with cancer. But, as expected, retrospective studies showed an overall decrease in CLABSI rates when cases of mucosal barrier injury were considered separately (5). Thus, whether lower rates after 2013 reflect actual improvement in patient safety or are an artifact related to changes in classification remains unclear. Many factors have contributed to changes in CLABSI rates over time. Some changes have made a real impact on patient care. Conversely, others may have altered the numbers without improving outcomes. Facing this uncertainty, hospitalists should continue to ensure that central venous catheters are used for appropriate indications and removed when no longer necessary, and that bundled strategies for CLABSI prevention are rigorously implemented. Hospitals should also internally monitor CLABSI rates over time. In this way, internally consistent data, rather than comparisons with other institutions using alternative definitions or measurement strategies, may be used to assess progress. We may never know how much of the recent improvement in CLABSI rates is real versus how much is fake news. Regardless, we must continue to refine our definitions and data. After all, we should be zeroing in on zero when it comes to CLABSI. Our patients count on it.