Erratum to “Correspondence analysis is a useful tool to uncover the relationships among categorical variables” [J Clin Epidemiol 2010;63:638-646]

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• Copyright

The authors would like to report a coding error in the SAS procedure PROC CORRESP option for the Greenacre adjustment. Now corrected, this error has an impact on some results reported in our paper. In Table 6, only two dimensions should be retained for adjustment. The Greenacre-adjusted percentages of explained inertia for Dimension 1 should be 86.1% instead of 45.8%; for dimension 2, the value should be 0.56% instead of 17.9%. These revised results also affect the scaling of coordinates on the graph, showing a very strong single dimension in the data.

This SAS coding error would also affect all other papers using SAS to perform multiple correspondence analyses using the Greenacre adjustment method and authors are encouraged to review their findings.

A SAS hot fix is now available for download at: http://ftp.sas.com/techsup/download/hotfix/HF2/A52.html

The authors are grateful to Dr. Greenacre and Dr. O'Rourke for identifying this error.