Significant variation in the way hospitals measure and report acquired bloodstream infections points to problems with payment incentives and databases that compare institutions, according to a report published in Tuesday's Journal of the American Medical Association.
"Our findings suggest that there is local variation in central line-associated BSI surveillance performance at different medical centers, raising concern for the validity of inter-institutional rate comparisons," wrote the authors.
The researchers, including Michael Lin, MD, of Rush University Medical Center and others with the Centers for Disease Control and Prevention Prevention Epicenters Program, note that "hospital reimbursement is increasingly dependent on reported rates."
This, they said, creates "potential financial incentives for hospitals to underreport rates. Our study highlights the potential fallibility of traditional surveillance methods using partially subjective criteria and underscores the need for cautious interpretation of these results until more reliable measures or validation against objective measures can routinely be performed."
The researchers examined practices over 12-month periods at 20 intensive care units within four academic training medical centers "with strong interest in infection prevention and research." They used a computer algorithm reference standard that they applied retrospectively using criteria that adapted the same CDC surveillance definitions.
Surveillance practice variation is of two types, the way cases are found and the way they are classified, the authors wrote. First, case findings of potential bloodstream infections may be incomplete, in that a patient may have multiple positive blood cultures throughout a prolonged intensive care unit stay, "not all blood cultures may be investigated, especially if the infection preventionist does not have a systematic method of tracking blood culture results."
In the second type, classification, there is substantial variation in application of subjective aspects in the central line-associated BSI definition. "For example, infection preventionists (and clinicians) will not always agree whether a positive blood culture originated from a central line or from an extravascular source such as an intra-abdominal abscess as a secondary BSI."
Where definitive information is not available, "infection preventionists may differently classify ambiguous cases."
Further confounding standardization, there also may be qualitative differences at each institution, "such as local culturing practice, quality of medical documentation and strength of institutional oversight over infection prevention activities."
Most of the variability they found, however, "is explained by differences in infection preventionist performance of surveillance."
The researchers' conclusions are similar to those of Matthew Niedner, MD, and others who looked at 20 pediatric intensive care units earlier this year.
Recently, the CDC Prevention Epicenter researchers wrote, "poor sensitivity of surveillance, conducted by infection preventionists was found during a retrospective review of a sample of blood cultures with potential central line-associated BSI in six Australian hospitals using a CDC-adapted surveillance system with the same criteria used in the present study."
In conclusion, the CDC authors wrote that "inconsistent surveillance practice can have a significant effect on the relative ranking of hospitals, which threatens the validity of the metric used by both funding agencies and the public to compare hospitals." Because these rates are now in public report cards and are included with financial incentives that reduce rates paid by private insurers and federal payers, "we should seek and test surveillance measures that are as reliable and objective as possible," they wrote.
See Also:
A Call for Standardized Infection Detection Practices