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MaryLou Mullen, RRT
American Lung Association of Central New York Syracuse, NY

Brian Mullen, PhD
Syracuse University Syracuse, NY

JAMA. 1994;271(11):822.

	Since this article does not have an abstract, we have provided the first 150 words of the full text PDF and any section headings.

In Reply.

—We would like to clarify some confusions raised in the commentaries on our recent integration of the association between β-agonist use and death from asthma.¹ One confusion involves effect strength. When we describe an effect of mean r=.055 as being "extremely weak," we are using empirically established benchmarks²: large (r=.500), moderate (r=.300), and small (r=.100). The weight of the available evidence indicates that one can account for approximately 0.3% ([mean r=.055]²=.003) of the variation in whether an asthmatic patient lived or died by knowing whether they used β-agonists. Drs Alberg and Comstock disagree with our assessment of this effect as "extremely weak." We fail to see how it can be described in any other way.

Alberg and Comstock are correct in submitting that correlations can be misleading under some circumstances. However, they confuse the calculation of r as a . . . [Full Text PDF of this Article]

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