Clinical index may predict pneumonia risk among patients receiving coronary bypass surgery
A clinical prediction rule for predicting pneumonia risk among patients who have undergone coronary artery bypass grafting was derived and validated by a group of researchers from several institutions in North America.
The researchers wrote that “this index may prove to be useful in prioritizing receipt of preventive interventions.”
The study included data on 17,143 individuals who had undergone coronary artery bypass grafting at 32 hospitals in six U.S. states. The study duration was January 1999 through February 2004.
Pneumonia without a known aspiration etiology developed in 2% (n=361) of the patient population.
The researchers identified 13 independent predictors of pneumonia in the derivation subset of the population sample:
- BMI less than 18.5.
- Smoking history.
- Admission from a non-residential setting.
- Cancer history.
- Chronic obstructive pulmonary disease.
- Canadian Cardiovascular Society score greater than or equal to 3.
- Prior internal mammary artery coronary artery bypass grafting.
- Emergency status.
- Serum creatinine level greater than 1.2 mg/dL.
- Percutaneous transluminal coronary angioplasty.
- Blood transfusion.
- Preoperative vancomycin administration.
- Receipt of mechanical ventilation longer than 1 day.
The model-based rule was calibrated as Hosmer-Lemeshow x2=5.51; P=.70 in the derivation group. In the same group, the rule demonstrated a discrimination with an area under the receiver-operating characteristic curve (ROC AUC, 0.78).
In the validation cohort, the discriminatory ability was also reasonable (ROC AUC, 0.75; P=.18 for difference in ROC AUC between groups).
Kinlin LM et al. Clin Infect Dis. 2010;50:493-501.
