The antitussive effect of placebo treatment on cough associated with acute upper respiratory infection.

Objective: The objective of this study was to determine the effects of a placebo treatment on cough in patients with cough associated with acute upper respiratory tract infection (URTI).

Methods: Patients with dry or slightly productive cough associated with a history of URTI were recruited. Cough frequency (CF) over 15 minutes was recorded by means of a microphone connected to a pen recorder.