Multiple sclerosis (MS) is a chronic disease which causes inflammation and destruction of the nerves in within the brain and the spinal cord. This disease is one of the most common causes of disability in young adults. A ''relapse'' is a phenomenon that occurs when there is an acute attack of disability as a result of an acute attack on the nervous system. There is usually some degree of recovery after a relapse.

Rebif is licensed in the United Kingdom for the treatment of relapsing MS and is given 3 times a week by injections under the skin. The RebiSmart device is a new injection device which has been developed to help patients with injecting their Rebif treatment.

Currently, all treatments for MS are injectable and require long term patient commitment. Patient compliance to treatment is important for the therapy to work effectively and decrease the risk of relapse episodes. Using a device that makes it easy for patients to inject may potentially improve compliance to treatment and therefore potentially have an impact on the number of relapses patients experience. The RebiSmart device has been developed for patients to inject conveniently and in comfort. The device allows the patient to control certain parameters such as needle depth, needle speed, injection time etc, and also has extra features designed to ease the injection process, such as a dose history calendar and an on-screen injection guide. The aim of this study is to determine what percentage of patients liked using the RebiSmart device and found it ''easy'' or ''very easy'' to use. The study will also determine which of the device features were most useful to the patients.

Inclusion Criteria:

• Have relapsing remitting multiple sclerosis
• Between 18 to 65 years old inclusive
• Have been prescribed Rebif for the first time but not yet started treatment
• Rebismart as chosen device
• Be under review by MS nurse
• Having given written informed consent to participate in the study

Exclusion Criteria:

• Injections of Rebif given by someone other than the patient
• Patients unable to use the Rebismart device due to visual or physical impairment
• Patients unwilling to give informed consent
• Contra-indications to Rebif as defined in the Summary of Product Characteristics (SPC).
• Allergy to the antipyretic analgesics that will be advised as prophylaxis for flu-like symptoms

Patients, who are under regular review by a Multiple Sclerosis nurse, with relapsing remitting multiple sclerosis who have been prescribed Rebif and have chosen to use the RebiSmart device for drug administration.