OBJECTIVES Relapsing remitting multiple sclerosis (RRMS) is a chronic inflammatory disease representing the most common chronic neurological disorder in young adults. RRMS usually leads to permanent disability and as a result is a major cause of reduced working capacity due to neurological diseases. This abstract presents methods to evaluate working ability and quality of life in natalizumab-treated RRMS patients. METHODS A non-interventional study was performed in Germany. Patients treated with natalizumab for a maximum of three months prior to baseline were eligible for study participation. Demographic and occupational information was collected; DSS and EQ-5D-questionnaires were used.  Data were collected at baseline, after 6 months and after 12 months. Main objective was to evaluate productivity per year, by using the formula: (working hours per day*5 days per week*46 working weeks a year)-(days absent from work*working hours per year). To assess health economic cost savings, productivity has been valued monetarily by calculating a daily rate of working costs. Subgroup analysis divides the study population into employed, unemployed, patients with statutory sick pay and students. Analyses of variance and subsequent post hoc tests will be performed to identify subgroup differences. RESULTS Of 95 patients included by January 2014, 46.3% were employed. Average hours worked/day were 5.3 hours (employed: 6.5 hours); average number of days absent from work during the past half-year was 17.4 days (employed: 16.5 days). Calculated productivity per 6 months results in 569.6 hours (employed: 661.0), meaning  6,5540.40€ (employed: 7,634.55€) in monetarily valued productivity. CONCLUSIONS This non-interventional study aimed at providing new insights in the therapy of RRMS patients treated with natalizumab. The study’s intention was to show how an increase in working hours in employed patients as well as a decrease in days absent from work can lead to an increase in productivity. Study was funded by Biogen Idec.