Daclizumab demonstrated superior efficacy vs IM interferon beta-1a in DECIDE. DECIDE included PROs to assess impact of treatment from the patient's perspective. MSIS-29 score improvement was significantly greater for daclizumab at week 96. EQ-5D score improvement was significantly greater for daclizumab at week 96. Improvement in PROs with daclizumab was consistent with clinical/MRI outcomes.