I included some results in my thesis that some other PhD students included in theirs. Is this plagiarism?
You should cite the other publications, your authorship involvement and your noted contribution status.

You should also note that you are presenting the complete result set while the cited publications each contain a part thereof. You should informally notify the other authors of your intentions - this may not change your course of action but it would be useful to know that they don't intend to contest any of your work.