Antibiotic timing and diagnostic uncertainty in Medicare patients with pneumonia: is it reasonable to expect all patients to receive antibiotics within 4 hours?

Many organizations, including the Centers for Medicare & Medicaid Services, measure the percentage of patients hospitalized with pneumonia who receive antibiotics within 4 h of presentation. Because the diagnosis of pneumonia can be delayed in patients with an atypical presentation, there are concerns that attempts to achieve a performance target of 100% may encourage inappropriate antibiotic usage and the diversion of limited resources from seriously ill patients. This study was performed to determine how frequently Medicare patients with a hospital discharge diagnosis of pneumonia present in a manner that could potentially lead to diagnostic uncertainty and a resulting appropriate delay in antibiotic administration. Randomly selected charts of hospitalized Medicare patients who have received diagnoses of pneumonia were reviewed independently by three reviewers to determine whether there was a potential reason for a delay of antibiotic administration other than quality of care. Antibiotic administration timing, patient demographic, and clinical characteristics were also abstracted. Nineteen of 86 patients (22%; 95% confidence interval, 13.7 to 32.2) presented in a manner that had the potential to result in delayed antibiotic treatment due to diagnostic uncertainty. Diagnostic uncertainty was significantly associated with the lack of rales, normal pulse oximetry findings, and lack of an infiltrate seen on the chest radiograph. There was a nonsignificant trend toward a longer time until antibiotic treatment in patients with diagnostic uncertainty. Many Medicare patients in whom pneumonia has been diagnosed present in an atypical manner. Delivering antibiotic treatment within 4 h for all patients would necessitate the treatment of many patients before a firm diagnosis can be made.