The letter submitted by Crosbie and Woodhead1 pertaining to our study of azithromycin for prevention of acute chronic obstructive pulmonary disease (COPD) exacerbations2 contains a number of errors and misconceptions.

First, Crosbie and Woodhead stated that our study was not double-blind. The complete protocol (published as an on-line supplement to the manuscript) indicated that ‘This is a prospective, randomised, double-blind, placebo-controlled trial…’.1

Second, while Crosbie and Woodhead correctly note that …