TY - JOUR
T1 - Association of Diagnostic Coding with trends in hospitalizations and mortality of patients with pneumonia, 2003-2009
AU - Lindenauer, Peter K.
AU - Lagu, Tara
AU - Shieh, Meng Shiou
AU - Pekow, Penelope S.
AU - Rothberg, Michael B.
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/3/28
Y1 - 2012/3/28
N2 - Context: Recent reports suggest that the mortality rate of patients hospitalized with pneumonia has steadily declined. While this may be the result of advances in clinical care or improvements in quality, it may also represent an artifact of changes in diagnostic coding. Objective: To compare estimates of trends in hospitalizations and inpatient mortality among patients with pneumonia using 2 approaches to case definition: one limited to patients with a principal diagnosis of pneumonia, and another that includes patients with a secondary diagnosis of pneumonia if the principal diagnosis is sepsis or respiratory failure. Design, Setting, and Participants: Trends study using data from the 2003-2009 releases of the Nationwide Inpatient Sample. Main Outcome Measures: Change in the annual hospitalization rate and change in inpatient mortality over time. Results: From 2003 to 2009, the annual hospitalization rate for patients with a principal diagnosis of pneumonia declined 27.4%, from 5.5 to 4.0 per 1000, while the age- and sex-adjusted mortality decreased from 5.8% to 4.2% (absolute risk reduction [ARR], 1.6%; 95% CI, 1.4%-1.9%; relative risk reduction [RRR], 28.2%; 95% CI, 25.2%-31.2%). Over the same period, hospitalization rates of patients with a principal diagnosis of sepsis and a secondary diagnosis of pneumonia increased 177.6% from 0.4 to 1.1 per 1000, while inpatient mortality decreased from 25.1% to 22.2% (ARR, 3.0%; 95% CI, 1.6%-4.4%; RRR, 12%; 95% CI, 7.5%-16.1%); hospitalization rates for patients with a principal diagnosis of respiratory failure and a secondary diagnosis of pneumonia increased 9.3% from 0.44 to 0.48 per 1000 and mortality declined from 25.1% to 19.2% (ARR, 6.0%; 95% CI, 4.6%-7.3%; RRR, 23.7%; 95% CI, 19.7%-27.8%). However, when the 3 groups were combined, the hospitalization rate declined only 12.5%, from 6.3 to 5.6 per 1000, while the age- and sex-adjusted inpatient mortality rate increased from 8.3% to 8.8% (AR increase, 0.5%; 95% CI, 0.1%-0.9%; RR increase, 6.0%; 95% CI, 3.3%-8.8%). Over this same time frame, the age-, sex-, and comorbidity-adjusted mortality rate declined from 8.3% to 7.8% (ARR, 0.5%; 95% CI, 0.2%-0.9%; RRR, 6.3%; 95% CI, 3.8%-8.8%). Conclusions: From 2003 to 2009, hospitalization and inpatient mortality rates for patients with a principal diagnosis of pneumonia decreased substantially, whereas hospitalizations with a principal diagnosis of sepsis or respiratory failure accompanied by a secondary diagnosis of pneumonia increased and mortality declined. However, when the 3 pneumonia diagnoses were combined, the decline in the hospitalization rate was attenuated and inpatient mortality was little changed, suggesting an association of these results with temporal trends in diagnostic coding.
AB - Context: Recent reports suggest that the mortality rate of patients hospitalized with pneumonia has steadily declined. While this may be the result of advances in clinical care or improvements in quality, it may also represent an artifact of changes in diagnostic coding. Objective: To compare estimates of trends in hospitalizations and inpatient mortality among patients with pneumonia using 2 approaches to case definition: one limited to patients with a principal diagnosis of pneumonia, and another that includes patients with a secondary diagnosis of pneumonia if the principal diagnosis is sepsis or respiratory failure. Design, Setting, and Participants: Trends study using data from the 2003-2009 releases of the Nationwide Inpatient Sample. Main Outcome Measures: Change in the annual hospitalization rate and change in inpatient mortality over time. Results: From 2003 to 2009, the annual hospitalization rate for patients with a principal diagnosis of pneumonia declined 27.4%, from 5.5 to 4.0 per 1000, while the age- and sex-adjusted mortality decreased from 5.8% to 4.2% (absolute risk reduction [ARR], 1.6%; 95% CI, 1.4%-1.9%; relative risk reduction [RRR], 28.2%; 95% CI, 25.2%-31.2%). Over the same period, hospitalization rates of patients with a principal diagnosis of sepsis and a secondary diagnosis of pneumonia increased 177.6% from 0.4 to 1.1 per 1000, while inpatient mortality decreased from 25.1% to 22.2% (ARR, 3.0%; 95% CI, 1.6%-4.4%; RRR, 12%; 95% CI, 7.5%-16.1%); hospitalization rates for patients with a principal diagnosis of respiratory failure and a secondary diagnosis of pneumonia increased 9.3% from 0.44 to 0.48 per 1000 and mortality declined from 25.1% to 19.2% (ARR, 6.0%; 95% CI, 4.6%-7.3%; RRR, 23.7%; 95% CI, 19.7%-27.8%). However, when the 3 groups were combined, the hospitalization rate declined only 12.5%, from 6.3 to 5.6 per 1000, while the age- and sex-adjusted inpatient mortality rate increased from 8.3% to 8.8% (AR increase, 0.5%; 95% CI, 0.1%-0.9%; RR increase, 6.0%; 95% CI, 3.3%-8.8%). Over this same time frame, the age-, sex-, and comorbidity-adjusted mortality rate declined from 8.3% to 7.8% (ARR, 0.5%; 95% CI, 0.2%-0.9%; RRR, 6.3%; 95% CI, 3.8%-8.8%). Conclusions: From 2003 to 2009, hospitalization and inpatient mortality rates for patients with a principal diagnosis of pneumonia decreased substantially, whereas hospitalizations with a principal diagnosis of sepsis or respiratory failure accompanied by a secondary diagnosis of pneumonia increased and mortality declined. However, when the 3 pneumonia diagnoses were combined, the decline in the hospitalization rate was attenuated and inpatient mortality was little changed, suggesting an association of these results with temporal trends in diagnostic coding.
UR - http://www.scopus.com/inward/record.url?scp=84859406106&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84859406106&partnerID=8YFLogxK
U2 - 10.1001/jama.2012.384
DO - 10.1001/jama.2012.384
M3 - Article
C2 - 22474204
AN - SCOPUS:84859406106
SN - 0098-7484
VL - 307
SP - 1405
EP - 1413
JO - JAMA - Journal of the American Medical Association
JF - JAMA - Journal of the American Medical Association
IS - 13
ER -