Q: Can the same research data be published twice if analyzed differently?
Can one publish the same data twice if it is analyzed differently? For example, raw unaltered values are used in one publication but in the other, ratios are provided. In my opinion, although the resulting numerical data is different, the conclusion would be identical or somewhat similar.
Usually publishing the result of the same dataset is considered as overlapping publication. Especially if the hypothesis, raw data, main study findings, and conclusion of both the publications are the same, the one published later might be regarded as duplicate publication. This publication practice is strongly discouraged by the ICMJE guidelines. Such duplicate studies would likely be rejected by journals on ethical grounds.
If the authors of the second article believe that although their study used the same data, it is significantly different from the previous study, they should clearly mention about the previous study in the cover letter during submission. The previous study should be cited in the text of the manuscript and the fact that the second study was based on already published data should also been mentioned. The authors would also need to take permission from the journal where the similar study was published earlier.
The final decision on the ethical validity of such a study or report will entirely be an editorial decision of the journal where the second study is being submitted.