Can performance measures ignite antibiotic resistance?

September 4, 2006

Pneumonia is a disease that accounts for greater than 750,000 hospitalizations in Americans 65 years of age and older, with a mortality rate of approximately 7% and 12% within 30 days of onset. Since the late 1990s, the National Pneumonia Project of the Centers for Medicare & Medicaid Services has promoted hospital practices associated with improved outcomes, one of which is antibiotic administration within a specified time of hospital admission. CMS, along with other organizations, uses this as a performance measure and currently recommends that patients with pneumonia receive antibiotics within four hours of arrival at the hospital.

"It is premature that CMS makes these performance requirements, because the liberal use of antibiotics may lead to resistance and to side effects," said Humberto Jimenez, Pharm.D., an infectious disease clinical pharmacist at St. Michael's Medical Center, Newark, N.J., and assistant professor at the Ernest Mario School of Pharmacy, Rutgers, The State University of N.J.

Hospitals and physicians face increased pressure to improve their performance in order to get maximum reimbursement. Pneumonia is sometimes difficult to diagnose in a timely fashion. Elderly patients may present with atypical signs and symptoms, depending on underlying conditions and the organism causing the infection. So in order for hospitals and physicians to meet 100% compliance with CMS standards, they are forced to administer antibiotics to patients before a pneumonia diagnosis is confirmed.

Charts of hospitalized Medicare patients diagnosed with pneumonia were randomly selected and reviewed to determine if there was a logical reason for a delay of antibiotic administration other than quality of care. The results showed that 19 of 86 cases (22%) had the potential to delay antibiotic administration due to diagnostic uncertainty, such as lack of infiltrates on the chest X-ray. The study further shows that it may be inappropriate to expect hospitals to administer the first antibiotic dose to all patients with pneumonia within four hours.

Jimenez's position on the CMS recommendation is mixed. On the one hand, administering antibiotics to elderly patients who are severely ill early on may be warranted. However, he does not think CMS should impose its standards on all patients, because those who are not severely ill might receive antibiotics inappropriately, leading to side effects and resistance.

"Although administering the first antibiotic dose within four hours of presentation to the hospital may encourage inappropriate antibiotic use, there are data stating that a delay in antibiotic therapy may increase mortality in patients with pneumonia," Jimenez reasoned. One study has examined 297 hospitals and showed there is a reduced mortality when the first antibiotic dose is administered within four hours of patient admission to the hospital. In data analyzed from 14,069 hospitalized pneumonia patients aged 65 years, there was a 15% reduction in the 30-day mortality rate when the time the first antibiotic dose (TFAD) was administered was eight hours of presentation to the hospital.

Another study, published in Chest in July, included 451 patients with community-acquired pneumonia-the seventh-leading cause of death in the United States-and it is estimated that the cost of treatment exceeds $12 billion per year. In this study, a TFAD of greater than four hours was associated with increased mortality. "There may be independent risk factors that can increase mortality," said Jimenez. Altered mental state, absence of fever, absence of hypoxia, and increased age were significant predictors of TFAD of greater than four hours. After adjusting for these factors, an association between TFAD and mortality was not statistically significant.

At Jimenez's institution, which has a large elderly population, there is a liberal use of antibiotics (before a definitive confirmation of pneumonia). "This population often presents with atypical symptoms, and those patients admitted from a nursing home require broad-spectrum antibiotic coverage due to the increased risk of multi-drug-resistant organisms in healthcare-associated pneumonia."

Jimenez believes more research is needed to determine why a delay in antibiotic administration causes increased morbidity and mortality. Additionally, "we need to ensure that other factors do not contribute," he said.

CMS will soon require a diagnosis of pneumonia and radiographic evidence of it before its performance standards are applied, thus reducing the pressure to administer antibiotics before diagnosis of pneumonia is confirmed.

THE AUTHOR is a writer based in New Jersey.