Study Says Failure of Initial Antibiotic Therapy Leads to Higher Mortality Rates, Increased Costs

CHAPEL HILL, N.C. -- Research conducted by a team of investigators, including Dr. David J. Weber of the University of North Carolina at Chapel Hill Division of Infectious Diseases, shows that the failure of initial intravenous antibiotic therapy in hospital patients with complicated skin and skin structure infections may cost the U.S. healthcare system more than $800 million each year and result in increased patient deaths.

According to the study, patients experiencing initial antibiotic treatment failure were three times more likely to die in the hospital than were patients whose therapy did not fail. In addition, the patients whose therapy failed required hospitalization for twice the length of stay as the other patients, or an additional 4.3 days of antibiotic therapy and hospitalization.

The additional antibiotic therapy also resulted in a doubling of the cost of the patients' treatment, or an additional $4,778 in inpatient charges.

"The results of this study are alarming," Weber said. "They clearly demonstrate the harmful consequences of not selecting the right antibiotic for patients presenting with these serious infections."

Weber is professor of medicine and pediatrics at UNC's School of Medicine and of epidemiology at UNC's School of Public Health. He also is medical director of hospital epidemiology for the UNC Health Care System.

The large, multi-hospital study found that 24 percent of the 23,846 patients studied experienced failure of their initial IV antibiotic therapy. Ariel Berger, senior analyst at Policy Analysis Inc., led the study, which was presented as a poster at the 43rd annual meeting of the Infectious Disease Society of America in San Francisco today.

"This study demonstrates the need within the medical community for additional antibiotic therapy options for treating complicated skin infections," said Weber. "Physicians need antibiotics that provide coverage for a broad spectrum of infections in order to ensure better patient outcomes."

Patients in the study were treated primarily for cellulitis or post-operative wound infections and received either cefazolin, vancomycin, ampicillin-sulbactam, ceftriaxone, or vancomycin and piperacillin-tazobactam as initial therapy. Initial therapy failure occurred if a patient received any other IV antibiotics on the third day in the hospital or any day thereafter, or if the patient underwent drainage-debridement on the third day in the hospital or any day thereafter.

The study researchers estimate that more than 168,000 patients each year may fail the initial regular course of treatment for complicated skin and skin structure infections (cSSSIs). More than 700,000 patients are hospitalized annually in the United States with a primary diagnosis of cSSSIs. Initial IV antibiotic therapy for these patients often is the regular course of treatment.

In addition to Weber and Berger, other investigators in this study were Dr. John Edelsberg, medical director at Policy Analysis Inc.; Dr. Rajiv Mallick, senior director of global health outcomes assessment at Wyeth; and Dr. Gerry Oster, vice president of Policy Analysis Inc.

Funding for the study was provided by Wyeth.

Source: University of North Carolina at Chapel Hill