SALT LAKE CITY — Failure to prescribe antibiotics in accordance with current guidelines for the treatment of severe community-acquired pneumonia comes at an average cost of 3 extra days on mechanical ventilation, Dr. Andrew F. Shoor reported at the annual meeting of the American College of Chest Physicians.
Given a conservative estimated cost of $2,500 per day of mechanical ventilation, noncompliance with this guideline costs the health care system an average of $7,500 each time a patient with severe community-acquired pneumonia (CAP) is prescribed an antibiotic regimen other than one of those recommended in Infectious Diseases Society of America (IDSA) guidelines. That makes the rate of compliance with the IDSA guidelines a quality assurance yardstick worth measuring, said Dr. Shoor, associate director of pulmonary and critical care medicine at the Washington (D.C.) Hospital Center. He reported on 199 patients requiring mechanical ventilation for severe CAP who participated in a multicenter prospective registry. Of these, 40% received antibiotics not in accord with IDSA guidelines.
After controlling for numerous potential confounding variables—including comorbid illnesses, patient demographics, time to initiation of antibiotics, pathogen, disease severity, and corticosteroid therapy—the use of an antibiotic regimen that was not in accord with IDSA recommendations was associated with 3 extra days on mechanical ventilation. The only other independent predictor of increased duration of mechanical ventilation was the development of acute renal failure.
“The purpose of this study was to ask, 'Is there any value, in terms of resource use, to compliance with the guidelines?' If this [analysis] had shown there was no value to compliance, then making all these guidelines is foolish, and we should be focusing instead on other health care issues,” Dr. Shoor said.
“But these results suggest that while I may not be able to show cause and effect, the signal is definitely going the wrong way,” he added. “This impact is clearly detrimental and it's clearly independent of multiple confounders. It shows the rate of compliance matters. We can do things better and save money.”
Critical care specialists have much to learn from cardiologists with regard to performance measurement, he said. When quality improvement programs measure the percentage of a physician's patients who are prescribed a β-blocker after a myocardial infarction, for example, this is done based on good evidence that the therapy reduces cardiovascular morbidity and mortality.
“We haven't done that very well in critical care. We have a host of guidelines—sepsis, ventilator-assisted pneumonia, community-acquired pneumonia—but we haven't made the effort yet to see if whether we use them or not affects outcomes. And I think we have to,” he said.
He readily conceded that the association between noncompliance with the IDSA guideline and the lengthier mechanical ventilation identified in his study doesn't prove causality. That would require a randomized trial. And for ethical reasons, there will never be a trial in which some critically ill participants are randomized to guideline-noncompliant antibiotic treatment. An observational study with rigorous attempts to control for potential confounders, such as this one, is a practical alternative, he said.
An intriguing finding in this study, Dr. Shoor noted, is that the actual adequacy of antibiotic therapy, as demonstrated by bacterial culture results, didn't differ between the IDSA guideline-compliant and -noncompliant patient groups. Thus, the precise mechanism by which guideline noncompliance results in more time on the mechanical ventilator remains unclear. “You might think that IDSA guideline compliance works by increasing the initial adequacy of antibiotics, but that didn't seem to be the case.”
'The rate of compliance matters. We can do things better and save money.' DR. SHOOR