Background: Multiple sclerosis (MS) is a common, chronic, neurodegenerative condition associated with substantial healthcare and societal economic burden. Disease-modifying MS treatments have the potential to reduce health resource utilization (HRU), thereby reducing the attendant socioeconomic burden. Objective: This study aimed to compare health and societal resource use and productivity in patients with relapsing-remitting MS (RRMS) receiving cladribine tablets versus placebo over 96 weeks in the CLARITY study. Methods: The CLARITY study was a 96-week, randomized, double-blind, placebo-controlled study in patients with RRMS. HRU data, societal resource use and productivity data were collected at baseline and during scheduled patient visits, at 6-month intervals. The recall period for the HRU questionnaire was 3 months. The study was carried out at 155 sites across 32 countries worldwide. The intent-to-treat population comprised 1326 patients with RRMS randomized to cladribine 3.5¿mg/kg (n¿=¿433) or 5.25¿mg/kg (n¿=¿456) tablets or placebo (n¿=¿437). Patient subgroups with high baseline disease activity were identified based on criteria of =2 relapses in the previous year (n¿=¿392); =1 T1 gadolinium-enhancing (Gd+) lesion (n¿=¿413); and =2 relapses in the previous year plus =1 T1 Gd+ lesion (n¿=¿138). Cladribine tablets were administered in two (3.5¿mg/kg group) or four (5.25¿mg/kg group) short courses given at 4-week intervals at the start of a 48-week treatment period, followed by another two courses at the start of a subsequent 48-week re-treatment period. Interferon-ß rescue therapy was permitted from week 24. Intravenous corticosteroids were available for the treatment of neurological relapses. HRU outcomes included mean number of hospital days and emergency room (ER), clinic and home visits during each study period. Societal resource use and productivity outcomes included mean number of hours and days of paid assistance, mean patient and carer work days missed, and self-reported productivity. Results: The mean number of hospital days per patient over 96 weeks was lower in the cladribine tablets groups (3.5¿mg/kg group: -3.19 days; 5.25¿mg/kg group: -1.54 days [both p¿