- Written informed consent from at least 1 parent/care giver (legal guardian) and accompanying informed assent from the subject (where the subject is able to provide assent) prior to admission to the study. If applicable, subject must be able and willing to give assent to take part in the study according to the local requirement. The study investigator is accountable for determining a child's capacity to assent to participation in a research study, taking into consideration any standards set by the responsible independent ethics committee (IEC); subject and their legal guardian(s) understand that the study requires them to be treated on an outpatient basis; subject and their legal guardian(s) understand that they must comply with study medication and study assessments including recording of PEF and rescue SABA use, attending scheduled study visits, and being accessible by a telephone call.