CMS metric may prompt excessive antibiotic use
■ Pressed to measure up in public reports, physicians at one hospital may have been too quick to diagnose patients with pneumonia, researchers say.
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A new study says physicians are 39% more likely to misdiagnose hospital patients as having community-acquired pneumonia due to the high-stakes environment fostered by mandatory public reporting of quality measures -- in this case, whether pneumonia patients got antibiotics within four hours of arriving at the hospital.
The results, published in the Feb. 25 Archives of Internal Medicine, are similar to those found in a Chest study published last year and echo many physicians' complaints about the measure of initial antibiotic timing, known as door-to-needle time. A February 2007 Infection Control and Hospital Epidemiology study tied excessive use of antibiotics encouraged by the performance metric to a severe outbreak of Clostridium difficile at a small rural hospital.
The performance measure is part of the Joint Commission's and the Centers for Medicare & Medicaid Services' hospital quality reporting initiatives and was first rolled out in 2004. It represented a change from the earlier goal of getting antibiotics to hospital patients with community-acquired pneumonia within eight hours of arrival.
CMS said that beginning this month, it will not report hospitals' results on the four-hour antibiotic timing metric and report performance on a new, six-hour goal. The change still must go through the federal rule-making process.
How performance metrics drive changes in medical practice raises a larger question, experts say, about how best to balance the benefits of public reporting against the potential for negative unintended consequences.
"The process of reducing door-to-needle time to under four hours requires major changes in how ERs function," said Jack D. McCue, MD, co-author of the Archives study and clinical professor of medicine at the University of California, San Francisco, School of Medicine.
"When you make major changes in the way patients are handled in the ER, you have to be very careful that what you're doing is worth it. And I think everybody's conclusion from this adventure is that this is not worth it."
Dr. McCue and his colleagues retrospectively examined 548 adult admissions for pneumonia at the Franklin Square Hospital Center in Baltimore for six months before the four-hour antibiotic timing metric was rolled out, and for the same six-month period a year later.
Using criteria for diagnosing pneumonia developed as part of Food and Drug Administration-directed clinical trials of antibiotics, researchers found that pneumonia misdiagnoses at admission increased 36% under the four-hour goal, while discharge misdiagnoses went up 15%.
These misdiagnoses led to a 23% increase in delays in making the correct diagnosis under the four-hour goal, researchers found.
The shift to the four-hour measure
Massive retrospective studies of pneumonia patients had supported moving to the four-hour metric. For example, a March 22, 2004, Archives of Internal Medicine study found that elderly patients with pneumonia who received antibiotics within four hours of arrival were less likely to die in the hospital or within a month after discharge. But there are no randomized controlled trials showing the effectiveness of earlier antibiotic administration.
The door-to-needle time goal is "a moving target," said Mark L. Metersky, MD, professor of medicine in the division of pulmonary and critical care medicine at the University of Connecticut School of Medicine and a member of an expert panel for CMS' National Pneumonia Project.
"When this first started, there were just too many patients who were not getting antibiotics until they got up on the floor, which could take six, eight or 10 hours, and that was too long, and patients were dying from it," Dr. Metersky said. "Now that everyone is more cognizant of it and patients are getting antibiotics quicker, we have to examine these measures and make sure they're still having benefits."
It is better for patients with pneumonia to get antibiotics within four hours, but CMS compromised because they recognized "there may have been unintended consequences," he said.
Dr. McCue said the change to six hours is "a weak attempt at saving face," and the evidence is not strong enough to support the measure.
Dale W. Bratzler, DO, helped conduct much of the research showing that earlier administration of antibiotics can save lives. He said the argument that measuring door-to-needle time performance drives doctors to err on the side of a pneumonia diagnosis "makes no sense at all."
In 2005, after the study period, changes to the measure clearly spelled out that if a physician is uncertain about a pneumonia diagnosis, that patient will be excluded from reporting, Dr. Bratzler said.
"This is a single-institution study, and it doesn't, in my opinion, provide evidence that there's a systematic problem across hospitals," added Dr. Bratzler, who is medical director of the Oklahoma Foundation for Medical Quality in Oklahoma City.