Correction (wileyonlinelibrary.com) DOI: 10.1002/sim.6088

Published online 8 January 2014 in Wiley Online Library

Correction for ‘Causal inference, probability theory, and graphical insights’ One should clarify that the numbers in Table 1 of Stuart Baker’s article [1] contain unfortunate numerical errors. The numbers with Y D 0 and Y D 1 for the not treated (X D 0) and the treated (X D 1) under the heading ‘U D ‹’ should read as given in the succeeding text. Indeed, these numbers are just the sum of the respective cell frequencies in the U D 1 and U D 0 columns, and pr(Y D 1) equals 260=.260 C 140/ D 0:65 for the not treated and pr(Y D 1) equals 180=.180 C 220/ D 0:45 for the treated. The numbers given in the published paper result in pr.Y D 1/ D 300=.300 C 100/ D 0:75 for the not treated and pr.Y D 1/ D 100=.100 C 300/ D 0:25 for treated. Corrected part of Table 1: Table I. U=? Outcome Treatment XD0 XD0

YD0 140 220

YD1 260 180

pr.Y D 1/ 0.65 0.45

M ARCEL Z WAHLEN Institute of Social and Preventive Medicine University of Bern Switzerland E-mail: [email protected]

References 1. Baker SG. Causal inference, probability theory, and graphical insights. Statistics in Medicine 2013; 32:4319–4330.

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