In reply to the letter of DM Fleming, dated 13 December 2005, in which he raises the issue of selection bias, we would like to point out that the randomisation prevented selection bias, although some residual bias (or confounding) cannot be precluded in small trials such as ours. That, for example, was the reason why we adjusted for a slight, but important imbalance in the age distributions between the groups.1
We reported an adjusted number needed to …