In this article [1], equation (8) is incorrect because it omitted the covariance terms. Let h denote the number of strata, so s = 1,2,...,h. Let T denote transpose, • denote matrix product, and Diagonal Matrix [vector] denote a matrix of all 0's except for vector on the diagonal. The correct formula is
![](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2F1471-2288-4-1/MediaObjects/12874_2004_Article_59_Equa_HTML.gif)
where
![](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2F1471-2288-4-1/MediaObjects/12874_2004_Article_59_Equb_HTML.gif)
In our example, the effect of the correction was negligible; the corrected estimated standard error was the same to two significant digits as the incorrect value.
Also for clarification, we note that in the sentence after (11), it is an assumption that, within stratum s, the difference, Δ s , does not depend on the unobserved covariate x.
References
Baker SG, Freedman LS: A simple method for analyzing data from a randomized trial with a missing binary outcome. BMC Medical Research Methodology. 2003, 3: 8-10.1186/1471-2288-3-8.
Pre-publication history
The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2288/4/1/prepub
Author information
Authors and Affiliations
Corresponding author
Additional information
The online version of the original article can be found at 10.1186/1471-2288-3-8
Rights and permissions
This article is published under an open access license. Please check the 'Copyright Information' section either on this page or in the PDF for details of this license and what re-use is permitted. If your intended use exceeds what is permitted by the license or if you are unable to locate the licence and re-use information, please contact the Rights and Permissions team.
About this article
Cite this article
Baker, S.G., Freedman, L.S. Erratum to: A simple method for analyzing data from a randomized trial with a missing binary outcome. BMC Med Res Methodol 4, 1 (2004). https://doi.org/10.1186/1471-2288-4-1
Received:
Accepted:
Published:
DOI: https://doi.org/10.1186/1471-2288-4-1