Explanation for the choice of comparators {6b}
PEx
The PEx cohort is observational; therefore, no specific interventions are defined for this cohort. For the purpose of reporting a sub-study from the PEx cohort, a PERIT intervention is considered to be any treatment, procedure, or strategy used in the acute management of a PERIT. PERIT interventions in the sub-studies are grouped into therapeutic domains comprising sets of mutually exclusive interventions, for example, sets of backbone antibiotics, sets of adjunctive antibiotics, sets of mucolytic therapies, sets of alternative physiotherapeutic regimens, and sets of immunomodulator treatments.