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Simplification of the IDSA/ATS criteria for severe CAP using meta-analysis and observational data
Waleed Salih1, Stuart Schembri, James D Chalmers
1University of Dundee, Ninewells Hospital and Medical School, Dundee, UK.
Abstract:
The 2007 Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) guidelines proposed "minor" criteria to predict intensive care unit (ICU) admission in patients with community-acquired pneumonia. These criteria were based on expert opinion. Consequently, the authors of the guidelines asked investigators to determine whether the score could be simplified by excluding noncontributory variables. Each IDSA/ATS minor criterion was validated using a random effects meta-analysis of seven studies. Variables present in <5% of cases or that were nonsignificantly associated with mortality/ICU admission were excluded. A simplified score excluding these variables was tested for prediction of mortality and ICU admission in an established database. Prediction was assessed using the area under the receiver operator characteristic curve (AUC). Leukopenia (<4000 cells·mm(-3)), thrombocytopenia (<100,000 cells·mm(-3)) and hypothermia <36°C occurred in <5% of cases. A simplified score excluding these variables was performed similarly for prediction of mortality, AUC 0.77 (95% CI 0.73-0.81) versus 0.78 (95% CI 0.74-0.82) (p=0.9) and intensive care unit admission, AUC 0.85 (95% CI 0.82-0.87) versus 0.85 (95% CI 0.82-0.88) (p=0.9). Additional predictors suggested by the IDSA/ATS were associated with mortality and ICU admission, but only incorporating acidosis (pH <7.35) altered the AUC (0.82 (95% CI 0.78-0.86) (p=0.6) for mortality and 0.86 (95% CI 0.82-0.88) (p=0.8) for ICU admission). No improvements were statistically significant. The IDSA/ATS criteria can be simplified by removing three infrequent variables.
Insights
The Infectious Diseases Society of America (IDSA) and American Thoracic Society (ATS) criteria for community-acquired pneumonia ICU admission can be simplified. Removing three infrequent variables did not significantly impact the prediction of mortality or ICU admission.
Area of Science:
- Infectious Diseases
- Critical Care Medicine
- Clinical Epidemiology
Background:
- The 2007 Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) guidelines introduced "minor" criteria to predict intensive care unit (ICU) admission for community-acquired pneumonia (CAP).
- These criteria were based on expert opinion, prompting a need for validation and potential simplification by excluding noncontributory variables.
Purpose of the Study:
- To validate each IDSA/ATS minor criterion using a random effects meta-analysis.
- To simplify the existing score by excluding variables with low prevalence (<5%) or nonsignificant association with mortality/ICU admission.
- To assess the predictive performance of a simplified score for mortality and ICU admission in CAP patients.
Main Methods:
- A random effects meta-analysis of seven studies was conducted to validate IDSA/ATS minor criteria.
- Variables with <5% prevalence (leukopenia, thrombocytopenia, hypothermia) or nonsignificant association with outcomes were excluded.
- A simplified score was tested on an established database, with prediction assessed using the area under the receiver operator characteristic curve (AUC).
Main Results:
- Leukopenia, thrombocytopenia, and hypothermia were present in <5% of cases.
- The simplified score demonstrated similar predictive performance for mortality (AUC 0.77 vs. 0.78) and ICU admission (AUC 0.85 vs. 0.85) compared to the original criteria.
- Incorporating acidosis showed no statistically significant improvement in AUC for mortality or ICU admission prediction.
Conclusions:
- The IDSA/ATS criteria for predicting ICU admission in CAP can be simplified by removing three infrequent variables.
- Simplification does not compromise the predictive accuracy for mortality or ICU admission.
- This simplification may enhance the clinical utility and ease of application of the prediction score.
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