Frequency of Hoover's sign in stable patients with chronic obstructive pulmonary disease

Hoover's sign (the inward motion of the lower lateral rib cage with inspiration) is conventionally considered to be a sign of severe disease in chronic obstructive pulmonary disease (COPD). However, no studies have been done regarding the frequency of Hoover's sign in patients with stable COPD. We aim to establish the frequency of Hoover's sign in a large series of stable patients with COPD and to analyse the characteristics associated with its presence. One hundred and fifty-seven consecutive patients with COPD, 150 of whom were men (95%), with a mean (standard deviation) age of 68 (8) years were included. Seventy-one patients had Hoover's sign (45%) on clinical examination. Hoover's sign was not detected in mild COPD patients, and it was present in 36% of moderate, 43% of severe and 76% of very severe COPD patients. In the multivariate analysis, dyspnea, body mass index (BMI), number of exacerbations and number of prescribed drugs were independently associated with the presence of Hoover's sign in COPD. Hoover's sign is a frequent finding in COPD, and the frequency increases with severity. Its presence is independently related to higher values of dyspnea, BMI, number of exacerbations and number of prescribed drugs.