Healthcare News & Insights

Pneumonia mortality rate drop questioned

If you look at recent reports of the mortality rate of patients hospitalized with pneumonia, you’ll see a steady decline. That can only mean advances in clinical care and improvements in quality are saving more patients, right?

Not so fast …

A recent study, which appeared in the Journal of the American Medical Association, found the drop in the pneumonia mortality rates could actually reflect changes in diagnostic coding.

Dr. Peter Lindenauer of Baystate Medical Center in Springfield, MA, and colleagues, analyzed Nationwide Inpatient Sample data of approximately 1.9 million patients hospitalized from 2003 to 2009 in three diagnostic categories:

  • Pneumonia as a primary diagnosis
  • Sepsis as the primary diagnosis with pneumonia as a secondary diagnosis, and
  • Respiratory failure as the primary diagnosis with pneumonia as a secondary diagnosis.

After analyzing all of the data, the researchers found:

  • hospitalization declined substantially (27.4%) in the group with pneumonia as the primary diagnosis, and mortality decreased 1.6% in this group
  • hospitalization skyrocketed (177.6%) in the group with sepsis as the primary diagnosis and pneumonia as its second, and its inpatient mortality rates decreased 2.9%, and
  • the third group with respiratory failure as the primary diagnosis and pneumonia as its secondary had a slight increase (9.3%) in hospitalization and mortality declined 5.9%.

But when the three groups were combined, the hospitalization rate declined only by 12.5% and inpatient morality rates increased 0.5%.

As a result of the study, Dr. Lindenauer and his colleagues noted that charts for patients with severe pneumonia increasingly listed non-pneumonia conditions as the primary diagnosis.

Therefore, one can’t assume that the reduction in pneumonia mortality rates are a direct result from real-world outcomes – as there have been no major changes in treatment to account for it. A more likely explanation for the decline is that the changes in mortality rates are a result of changes in diagnostic coding.

Even though the U.S.  is moving toward the implementation of ICD-10, which provides greater specificity in diagnostic coding, it probably won’t change the study.


There will still be the potential for misleading interpretation of studies based on administrative data.








Subscribe Today

Get the latest and greatest healthcare news and insights delivered to your inbox.