As disclosed on our website (see author guidelines), on this FAQ (Why has my article been transferred to another journal (or a transfer has been suggested), and what are my options?) as well as during the submission process (submission checklist, see below), all JMIR journals use a system of portable peer-review (also called cascading peer-review). This is a system which is not unique to JMIR Publications, but used by many other publishers as well:
"Apart from reducing the redundancy of having a paper shepherded through the peer-review process a second or third time, internal manuscript and peer-review referral services offers real value to the submitting author — i.e., faster publishing." (Phil Davis, Scholarly Kitchen)
We clearly disclose this system to our authors. On submission, there is a checklist which all authors have to go through. One of the checklist items spells out the cascading peer-review process as follows:
Authors must check this item to indicate that they have read and understood our policy. If authors want to opt out, or have only specific journals considered, they can mention this in their cover letter. If authors do not opt out, we may transfer a submission to another journal if the paper is rejected for the journal it was originally submitted to, or if we feel it is a better fit for another JMIR journal (see Why has my article been transferred to another journal (or a transfer has been suggested), and what are my options?).