The Avonex Fifteen-year Long-term Follow-up of Patients with Relapsing Multiple Sclerosis: ASSessment of Drug Utilization, EaRly TreAtmeNt, and Clinical OutcomEs (ASSURANCE), was a single-time-point evaluation of patients conducted 15 years after the pivotal MSCRG study, evaluated the impact of IM IFNβ-1a treatment on long-term disability and Quality of Life outcomes in patients who completed 2 years in a previous Multiple Sclerosis Collaborative Research Group (MSCRG) study.

The primary objective of this study is to determine the impact of early versus delayed initiation of treatment on the long-term physical status of patients with relapsing forms of MS measured by the self-reported EDSS.

Primary endpoints for this study were as follows:

1. Changes in EDSS score from baseline for original Avonex® pivotal trial
2. Percentage of patients with EDSS scores less than or equal to 4
3. Percentage of patients with EDSS scores less than or equal to 6
4. Percentage of patients with EDSS scores less than or equal to 7

Secondary endpoints were:

1. Percentage of patients alive
2. Percentage of patients living independently
3. SF 36 Quality of Life status
4. Self-reported VAS of independence with self-care

Inclusion Criteria:

1. Patients having completed at least 2 years of treatment (Avonex® or placebo) in the original Avonex® pivotal trial.
2. Subjects (or their caregivers) must be willing to complete a multi-page questionnaire.
3. Signed written informed consent form

Exclusion Criteria:

1. Unwillingness or inability to comply with the requirements of this protocol.
2. Any other reasons that, in the opinion of the Investigator, the subject is determined to be unsuitable for enrollment into this study

Patients having completed at least 2 years of treatment (Avonex® or placebo) in the original Avonex® pivotal trial.