Predictors of van der Valk et al for Distinguishing a Patient with Bacterial from Nonbacterial Exacerbation of Chronic Obstructive Pulmonary Disease (COPD)

A bacterial infection was associated with the exacerbation in 19% of cases.

Parameters:

(1) Gram stain of sputum

(2) number of exacerbations in past 12 months

(3) clinically relevant decrease in FEV1 (> 12% decrease and > 200 mL)

decrease in FEV1 in mL in 1 second =

= (baseline FEV1 in mL) - (admission FEV1 in mL)

percent decrease in FEV1 =

= ((baseline FEV1) - (admission FEV1)) / (baseline FEV1) * 100%

where:

• Change in FEV1 was used to define lung function. A clinically relevant decrease was > 12% and > 200 mL from baseline.

• A positive sputum Gram stain was based on identification of pathogenic or potentially pathogenic bacteria. White blood cells were not considered.

total number of predictors =

= SUM(points for all 3 parameters)

Interpretation:

• minimum number of predictors: 0

• maximum number of predictors: 3