Stephen J.LurieMD, PhD, Senior EditorIndividualAuthor
Copyright 2002 American Medical Association. All Rights Reserved.
Applicable FARS/DFARS Restrictions Apply to Government Use.2002
To the Editor: Dr Wirth and Ms Krause1 reported that sibutramine resulted in similar amounts
of weight loss among obese patients whether given as an intermittent therapy
(IT) or as continuous therapy (CT), compared with placebo. We have 4 concerns
with the study and its conclusions.
First, the authors make statistical comparisons starting at 4 weeks
in all 3 groups. Although both the IT and CT groups had had a 4-week run-in,
there was no difference in treatment between the IT and CT groups until week
12. In effect, the IT group had a 12-week run-in. This makes comparison using
4-week values as a starting point invalid. Either there should not have been
a sibutramine run-in period at all, given that only 23 of 1102 patients were
excluded due to being nonresponders during this period, or the placebo group
should have stayed on sibutramine for 12 weeks as well to ensure an equivalent
baseline for all 3 groups. Alternatively, the authors could have included
a washout period for all groups after having had identified nonresponders
with a trial of sibutramine. The importance of this is most evident in Figure
2A of the article by Wirth and Krause, which shows weight trends of men during
the study. Using week 12 as the true starting point for comparison, there
was apparently a significant weight gain in the IT group.
Ransom T, Ur E. Measuring the Effect of Sibutramine for Weight Loss. JAMA. 2002;287(4):449-450. doi:10.1001/jama.287.4.447