Development of a signs and symptoms outcome measure for caregivers of patients with methylmalonic acidemia and propionic acidemia (MMAPAQ).

This study establishes the content validity of the MMAPAQ as the first ObsRO questionnaire for measuring core signs and symptoms of MMA and PA in clinical trials and community research. Scoring and psychometric measurement properties of the MMAPAQ will be established in future studies. The PedsQL™ was found to have face validity in measuring concepts that affect the MMA and PA patient populations and should also be considered for use in clinical trials in MMA and PA.