To the Editor: Dr Geba and colleagues1 reported that rofecoxib, 25 mg/d, was superior
to celecoxib, 200 mg/d, and acetaminophen, 4000 mg/d, in treating osteoarthritis
(OA) of the knee. We lack important information for supporting this conclusion.
First, it is known that patients are more likely to comply with once-daily
regimens2 and that morning doses are less
likely to be omitted.3 The report of the
trial implied that the cyclooxygenase 2 (COX-2) inhibitors and their placebos
were taken once daily, in the morning, while acetaminophen and its placebo
were taken 4 times daily. Therefore, it is likely that suboptimal compliance
had a large impact on the effect of acetaminophen. It would be helpful to
the reader for the authors to report the compliance for the different groups,
and to perform a subanalysis for efficacy in highly compliant patients.