Accuracy of symptoms, signs, and C-reactive protein for early chronic obstructive pulmonary disease.

Background: Guidelines recommend detection of early chronic obstructive pulmonary disease (COPD), but evidence on the diagnostic work-up for COPD only concerns advanced and established COPD.

Aim: To quantify the accuracy of symptoms and signs for early COPD, and the added value of C-reactive protein (CRP), in primary care patients presenting with cough.

Design And Setting: Cross-sectional diagnostic study of 73 primary care practices in the Netherlands.