M.D.: Not much evidence that drug stewardship works

Donald Goldmann, M.D., who has studied antibiotic resistance for 20 years, said community-acquired methicillin-resistant Staphylococcus aureus (MRSA) is infiltrating hospitals and "it is a pandemic that will not be controlled. It is going to fundamentally alter how we use antibiotics and how we attempt to control them."

Nobody knows enough about what to do, and research is not telling us very quickly, stressed Goldmann, senior VP of the Institute of Healthcare Improvement and professor of pedatrics at Harvard Medical School. Speaking at the National Foundation for Infectious Diseases conference on microbial resistance, in Bethesda, Md., he said he's particularly unimpressed with the evidence on promoting more careful use of antibiotics to prevent resistance. Now, he said, MRSA spread represents a new enemy at the gates.

MRSA, which is resistant to most common antimicrobial drugs, has gotten much worse in the past few years. Centers for Disease Control & Prevention surveys indicate that in U.S. intensive care units, the proportion of S. aureus nosocomial infections that are resistant to methicillin rose from less than 40% to over 60% from 1992 to 2003. CDC also said MRSA is an increasing cause of community-onset infection, including growing numbers of problems in "persons without identified predisposing risk, including recent healthcare exposure."

With regard to MRSA and the emergence of resistant pathogens in hospitals in general, Goldmann said, "As concern turns to panic, advocates of various approaches are becoming more insistent-even strident-in their views." Yet while most groups call for some combination of antibiotic stewardship and infection control, he contended that there is not enough evidence to show antibiotic stewardship efforts in hospitals are effective. With few exceptions it is not possible to draw conclusions about effects on microbiological or clinical outcomes, he said. One problem is that "pharmacists were the principal deliverers of interventions, and they used prescribing data as the only outcome measure."

Although Goldmann said no aspect of antimicrobial resistance has been adequately studied, he has more faith in hospital infection control, saying without it "antibiotic stewardship is almost certainly going to fail miserably." He pointed particularly to data from Europe showing levels of MRSA vary greatly from country to country and from hospital to hospital. He thinks aggressive infection control makes the difference-not genotype of the microbe; or the size, design, or age of hospitals; or case mix.

Goldmann said that, in hospitals with low infection rates, "there is an attitude that every infection is intolerable." That culture is obvious in hospitals in Denmark and the Netherlands, where MRSA infection levels are very low. "Basically, if a second case of MRSA appears in a unit, all the employees are cultured, the positives are sent home, the unit is closed, they decolonize everybody who is colonized. It's extremely aggressive," he said. In contrast, here, he lamented, the current "defect rate" of failing to follow basic procedures of screening cultures, isolation, and hand hygiene is 60% to 80%. "These are preventable adverse events. We should stop talking as if they're inevitable rites of passage."

In the same session, Rob Owens, Pharm.D., maintained that with encroaching resistance, there is a time to use the more expensive antimicrobials, even from an economic perspective: "A more expensive antimicrobial agent that may reduce length of stay might reduce overall costs."

But Owens, who is with the Maine Medical Center in Portland, said that economic studies have not been of a quality to convince hospital management of when the more expensive antimicrobials are more cost-effective.

Kathryn Foxhall is a writer based in the Washington, D.C., area.