Table 1.

Additional guidance for scoring the 10 PRECIS domains in the context of the BLISTER trial

PRECIS domain	Description in the context of BLISTER
Eligibility criteria	Are most patients who would normally be treated included in the trial? How strict are the criteria?
Follow-up intensity	How similar to normal practice is the patient follow-up?
Primary outcomes	Would those considered to be a treatment success in the trial (for example, three or fewer blisters present at six weeks of follow-up) also be considered a treatment success in practice?
Method of analysing the primary endpoints	Are there many exclusions from the analysis? How inclusive is the definition of per-protocol?
Doxycycline and prednisolone flexibility	Can trial treatments be altered during follow-up or are patients expected to stay on the prescribed dose? Is this any different to normal practice?
Practitioner expertise on doxycycline and prednisolone	Are patients seen by specialists? Would they normally be seen by, for example, general practitioners?
Participant compliance	How closely is this measured? Are there interventions made to maintain or improve compliance?
Practitioner adherence to the protocol	Is the study concerned whether investigators ‘customise’ the trial to suit their own setting? Are all investigators expected to treat patients in the same way?