An 85 year old male presents with complaints of a cough. On initial observation, a barrel chest deformity and pursed lip breathing is noted.

An 85 year old male presents with complaints of a cough. On initial observation, a barrel chest deformity and pursed lip breathing is noted. The clinician is immediately suspicious of COPD, but also understands which of the following to be true?

A barrel chest may be an illusion and increases the probability of COPD by less than 15%

Pursed lip breathing is pathognomic (diagnostic) for COPD

The absence of accessory muscle use always argues against the presence of COPD

The finding of barrel chest has high specificity and, therefore, it's presence is highly diagnostic for COPD