In Reply.—
Dr Brooks aptly cautions that one may not appropriately base intergroup comparisons on criteria used to define the groups. We specifically indicated our intention not to do so in pointing out the folly of such "circular reasoning" in the manuscript's penultimate paragraph. We do not cite the statistical significance of SIDS intergroup differences. We do wish to emphasize the lack of differences in 5-minute Apgar score and growth velocity when the "classic SIDS" group is compared to appropriate controls.
Circular reasoning. Forbonnais and the intricate history of circular flow analysis in the 1750s
