Variation in diagnostic coding of patients with pneumonia and its association with hospital risk-standardized mortality rates: a cross-sectional analysis.
BACKGROUND
Most U.S. hospitals publicly report 30-day risk-standardized mortality rates for pneumonia. Rates exclude severe cases, which may be assigned a secondary diagnosis of pneumonia and a principal diagnosis of sepsis or respiratory failure. By assigning sepsis and respiratory failure codes more liberally, hospitals might improve their reported performance.


OBJECTIVE
To examine the effect of the definition of pneumonia on hospital mortality rates.


METHODS
Cross-sectional study.


METHODS
329 U.S. hospitals.


METHODS
Adults hospitalized for pneumonia (as a principal diagnosis or secondary diagnosis paired with a principal diagnosis of sepsis or respiratory failure) between 2007 and 2010.


METHODS
Proportion of patients with pneumonia coded with a principal diagnosis of sepsis or respiratory failure and risk-standardized mortality rates excluding versus including a principal diagnosis of sepsis or respiratory failure.


RESULTS
When the definition of pneumonia was limited to patients with a principal diagnosis of pneumonia, the risk-standardized mortality rate was significantly better than the mean in 4.3% of hospitals and significantly worse in 6.4%. When the definition was broadened to include patients with a principal diagnosis of sepsis or respiratory failure, this rate was better than the mean in 11.9% of hospitals and worse in 22.8% and the outlier status of 28.3% of hospitals changed. 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% and worsened in 40.9%. Among those in the lowest quintile, 20.0% improved and none worsened.


CONCLUSIONS
Only inpatient mortality was studied.


CONCLUSIONS
Variation in use of the principal diagnosis of sepsis or respiratory failure may bias efforts to compare hospital performance regarding pneumonia outcomes.


BACKGROUND
Agency for Healthcare Research and Quality.
Michael B
MB
Rothberg
Penelope S
PS
Pekow
Aruna
A
Priya
Peter K
PK
Lindenauer
D000328:Adult; D059019:Clinical Coding; D003430:Cross-Sectional Studies; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units; D038801:International Classification of Diseases; D008297:Male; D018410:Pneumonia, Bacterial / Q000175:diagnosis* / Q000401:mortality* / Q000628:therapy; D012121:Respiration, Artificial; D012131:Respiratory Insufficiency / Q000175:diagnosis / Q000401:mortality; D018570:Risk Assessment; D018805:Sepsis / Q000175:diagnosis / Q000401:mortality; D014481:United States; D055815:Young Adult