Pneumonia mortality higher under broader definition

Hospital mortality rates for pneumonia are much higher under a broader definition of the illness, according to a study published in the Annals of Internal Medicine.

Researchers, led by Michael B. Rothberg, M.D., of the Cleveland Clinic, analyzed inpatient mortality rates among adult patients hospitalized for pneumonia between 2007 and 2010 at 329 hospitals. They found that 4.3 percent of hospitals had a significantly better risk-standardized mortality than average, and 6.4 percent had significantly worse than average risk-standardized mortality when they restricted the patient sample to those with pneumonia as their principal diagnosis, according to the study.

When researchers expanded the definition to incorporate patients with pneumonia whose principal diagnosis was respiratory failure or sepsis, 11.9 percent of hospitals had better-than-average mortality rates, compared to 22.8 percent with worse-than-average rates. Under the expanded definition, outlier status changed for 28.3 percent of hospitals.

"Among hospitals in the highest quintile of proportion of patients coded with a principal diagnosis of sepsis or respiratory failure, outlier status under the broader definition improved in 7.6 percent and worsened in 40.9 percent," researchers wrote. "Among those in the lowest quintile, 20.0 percent improved and none worsened."

Therefore, they concluded, variation in use of the principal diagnosis of sepsis or respiratory failure may bias efforts to compare hospital performance regarding outcomes of pneumonia.

In addition to mortality rates, pneumonia is also the seventh most expensive inpatient condition to treat, according to research published last year by the Agency for Healthcare Research and Quality. Treatment cost U.S. hospitals nearly $11 billion in 2011, FierceHealthcare previously reported. However, a recent report card from the Niagara Health Quality Coalition indicated that overall pneumonia mortality rates for hospitals dropped from 8.2 percent to 3.6 percent over the past decade.

To learn more:
- here's the study abstract