Two research groups conducted separate randomized controlled trials of an investigational targeted therapy for a certain disease versus: a) all conventional drugs b) one specific conventional drug. The studies were registered separately and had different patient cohorts, but were otherwise identical in their rationales and protocols, and had similar results. How should/might such 'twin' studies be published? Eg: back-to-back papers in one journal; a single paper with two results sections; two papers in different journals; a pooled analysis of data from both studies? Does anyone know of examples or publishing protocols?
Thanks for replying. To clarify, the research objectives are very similar; to compare a drug vs. Cohort 1) all conventional agents including the most widely used one; Cohort 2) only the most widely used one. So data from the first could answer both, but the second has a larger cohort than the subgroup of the first. Since journals discourage submission if a similar paper is submitted elsewhere, this may be an issue the publication strategy needs to address.
I would suggest contacting the journal in which you are interested in publishing and asking if they would publish the two side by side but as separate papers so that authors all benefit but the audience can see them as a unit.
I followed Dr Southern's sensible advice, and have likewise been advised by a leading general medical journal to submit separate stand-alone manuscripts, with a cover letter flagging each to the other.
In this example (Article Efficacy of multidomain interventions to improve physical fr...
), the results of two complementary RCTs were combined in a single article. This has the advantage of avoiding repetition in the introductions and methods sections of separate manuscripts.