A Web based real world observational study in Relapsing-Remitting Multiple Sclerosis (RRMS) population capturing outcomes reported by patients and by the physicians during 12 months after initiating or resuming Betaseron.

Inclusion Criteria:

• Provides written informed consent to participate in the study
• At least 18 but no more than 65 years old
• Documented clinical diagnosis of a relapsing form of multiple sclerosis or confirmed clinically isolated syndrome (CIS)
• Initiating Betaseron therapy, or resuming Betaseron after not having used it for at least three months
• Willing and able to provide a valid e-mail address which will be in use for the duration of the study
• Willing and able to complete study questionnaires via the Internet
• Has reliable Internet access for the duration of the study
• Completes the baseline patient questionnaire

Exclusion Criteria:

• Kurtzke Expanded Disability Status Scale (EDSS) score greater than 6.0
• Cognitive dysfunction that, in the Investigator's judgment, raises doubts about the study participant's ability to provide informed consent or accurately complete the monthly patient questionnaire
• Any use of Betaseron within the three months prior to study entry
• Inability to read, write, or speak the English language
• Illness or disease other than multiple sclerosis that the Investigator believes is likely to cause the patient's death or incapacity within twelve months
• Any severe, uncontrolled illness or condition that the Investigator believes could dominate the patient's quality of life
• Coexistent autoimmune disease such as rheumatoid arthritis, lupus, or psoriasis that is likely to be exacerbated by treatment with Interferon
• Current use of any immunosuppressive medication
• Previous participation in a multiple sclerosis (MS) clinical trial within the three months prior to study entry
• Previous use of monoclonal antibodies treating MS within the three months prior to study entry
• Current use of any secondary treatment for multiple sclerosis other than the episodic use of steroids during relapses or exacerbations

"real world" population