We performed a double-blind, multicenter, randomized
clinical trial to compare TMP-SMX and
clindamycin, each of which is commonly recommended
as empirical therapy for uncomplicated
skin infections in the outpatient population with
only minor or no coexisting conditions.6,7,15,16 The
cure rates with TMP-SMX and clindamycin did not differ significantly. The cure rate with TMP-SMX ranged from 5 percentage points higher to 7 to
10 percentage points lower than the cure rate with
clindamycin, on the basis of the 95% confidence
intervals for rate differences in the intention-totreat
population and the population that could
be evaluated. This well-powered superiority trial
did not show the superiority of either intervention.
Although it is not appropriate to claim that there are no differences on the basis of the negative
result of the superiority test, important differences
can reasonably be ruled out with the use
of confidence intervals. Adverse-event rates with
the two therapies were similar.