ARR, defined as the total number of confirmed relapses that occurred during the observation period divided by the total number of patient-years, with the result standardized to a 1-year period.

A relapse is defined as new or recurrent symptoms and objective typical findings of MS with a duration of at least 24 h, in the absence of fever or infection and preceded by a stable or improving neurological state for ≥ 30 days

A relapse is defined as new or recurrent symptoms and objective typical findings of MS with a duration of at least 24 h, in the absence of fever or infection and preceded by a stable or improving neurological state for ≥ 30 days

A relapse is defined as new or recurrent symptoms and objective typical findings of MS with a duration of at least 24 h, in the absence of fever or infection and preceded by a stable or improving neurological state for ≥ 30 days

The Expanded Disability Status Scale (EDSS) is the most widely disability scale used in MS. The scale ranges from 0 to 10 in 0.5 unit increments that represent higher levels of disability. Scoring is based on an examination by a neurologist.

Number of participants with presence of radiological disease activity on the cranial MRI

Percentage of participants reporting injection site reactions (ISR)

Percentage of patients with AEs leading to temporal or permanent discontinuation

Number of pregnancies and pregnancy outcome

Non-adherence, defined as skipping at least one dose during initial dosing (i.e. missing one weekly injections, defined as not receiving the dose within the established 7 and 14 days after the prior dose) or during maintenance dosing (missing one monthly injection, defined as not receiving the dose within the established month after the prior dose) as per SmPC.

Proportion of patients who discontinue ofatumumab during the observation period

The WPAI is an instrument to assess impairments in both paid work and unpaid work. Using six questions, it measures absenteeism, presenteeism as well as the impairments in unpaid activity because of health problem during the past seven days.

The first question is neutral. In the 2nd 3rd 5th and 6th questions a higher score means worse outcome. In the 4th question a higher score means better outcome.

Symbol Digit Modalities Test (SDMT) is a measure of sustained attention, processing speed, visual scanning, and motor speed. This test involves a coding schema consisting of nine abstract symbols, each paired with a number ranging from 1 to 9. The subject is required to scan the key and write down the number corresponding to each symbol as fast as possible. The score is the number of correctly coded items from 0-110 where higher scores indicate better result.

The MFIS-5 measures the impact of fatigue on cognitive, physical, and psychosocial function. The MFIS-5 is a self-administered questionnaire with a 5-point Likert scoring system that best indicates how often fatigue has affected patients during the past 4 weeks: 'never', 'rarely', 'sometimes', 'often' and 'almost always', each scored 0-4, respectively. It consists of 5 of the 21 items of MFIS that most strongly correlate with the total MFIS score. The sum provides a total score from 0 to 20. Higher scores indicate a higher perception of fatigue.

The EQ-5D-5L is a generic measure for Health-related quality of life. It consists of two pages: the EQ-5D descriptive system and the EQ visual analogue scale (EQ VAS). The descriptive system comprises five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has five levels( 1=no problems to 5= extreme problems). A summary index with a maximum score of 1 can be derived from these five dimensions by conversion with a table of scores. The maximum score of 1 indicates the best health state. The EQ VAS records the patient's self-rated health on a vertical visual analogue scale, where the endpoints are labelled 'The best health you can imagine' and 'The worst health you can imagine'. The VAS can be used as a quantitative measure of health outcome that reflect the patient's own judgement. In the VAS, 100 indicates the best health status.

The PGIC is a single, self-administered question asking respondents to rate how their condition has changed since a certain point in time. The PGIC will ask: "Since beginning treatment, how would you describe the change (if any) in activity limitations, symptoms, emotions and overall quality of life, related to your MS? Responses will range from 1= very much improved to 7= very much worse.

The CGI provides an overall clinician-determined summary measure that considers all available information, including the patient's history, psychosocial circumstances, symptoms, behavior, and the impact of the symptoms on the patient's ability to function.

The CGI-Improvement will be used in this study. The clinician compares the patient's overall clinical condition to the one week period just prior to the initiation of medication use. The following one query is rated on a seven-point scale: "Compared to the patient's condition at admission to the project [prior to medication initiation], this patient's condition is: 1=very much improved since the initiation of treatment; 2=much improved; 3=minimally improved; 4=no change from baseline (the initiation of treatment); 5=minimally worse; 6= much worse; 7=very much worse since the initiation of treatment.

The TSQM-9 is a widely used generic measure to assess treatment satisfaction with their medication.

The TSQM-9 uses nine of the 14 TSQM Version 1.4 items not including five TSQM questions related to side effects. The TSQM-9 encompasses three subscales that assess the patient's perception of medication effectiveness, convenience, and global satisfaction. Each TSQM-9 subscale consists of three items, with responses measured on a Likert scale ranging from 1 (low) to 7 (high). Subscale scores are usually transformed to a range from 0 to 100, with higher scores indicating greater satisfaction.