Pneumonia often misdiagnosed on patient readmissions, studies find

Researchers say the misdiagnoses led to overuse of antibiotics and increased health care costs. Pneumonia ranks second to congestive heart failure as the reason for readmission within 30 days of a previous hospitalization.

Led by Henry Ford Infectious Diseases physicians Hiren Pokharna, M.D., and Norman Markowitz, M.D., researchers found that:

• 72 percent of patients were misdiagnosed with pneumonia upon readmission to the same hospital.
• African-Americans were twice more likely than Caucasians to be misdiagnosed with pneumonia.
• Patients who smoke or have lung disease were likely to be misdiagnosed with pneumonia.
• 72 percent of the misdiagnoses occurred in the Emergency Department.
• Fewer than 33 percent of patients had any outpatient follow-up care prior to their readmission.

Results of the two companion studies will be presented Friday at the 48th annual meeting of the Infectious Diseases Society of America Oct. 21-24 in Vancouver.

"These studies show that we need to increase awareness among physicians about using the diagnostic standards and criteria set forth in the Centers for Disease Control and Prevention's National Healthcare Safety Network for diagnosing pneumonia at the time of readmission," says Dr. Pokharna, a fellow at Henry Ford and the lead author of the companion studies.

"This also points to the importance of using X-ray for ruling out pneumonia. And once pneumonia is ruled out, the antibiotics can be discontinued."

In seeking to explain the difficulty of diagnosing pneumonia and high prevalence of misdiagnoses, Henry Ford researchers examined medical records of 127 patients diagnosed with pneumonia between December 2008 and December 2009 and readmitted within 30 days of a previous hospitalization.

Researchers found that 92 of the 127 patients were misdiagnosed with health care associated pneumonia using CDC/National Healthcare Safety Network criteria. Health care associated pneumonia is a newly recognized form of pneumonia in patients who had recent close contact with a health care system, either through a hospital, outpatient dialysis center, nursing home or long-term care facility. The classification was added with the shift from hospital-based care to home-based care.

Researchers cited several reasons for the misdiagnoses, including pre-existing lung disease and abnormalities on chest X-rays.

The studies were funded by Henry Ford Hospital.