OBJECTIVES: Fatigue is one of the most common symptoms of relapsing multiple sclerosis (RMS). Considering its subjective aspect, using MS-specific patient reported outcomes to characterize it would grant a better understanding of its impact on patients’ quality of life (QoL). This study aimed to measure fatigue in RMS patients from multiple countries using the Fatigue Symptoms and its Impacts Questionnaire-Relapsing Multiple Sclerosis (FSIQ-RMS).

METHODS: This non-interventional prospective study was conducted via an online survey. 722 ambulatory adult patients with RMS were recruited: 300 in the US, 362 in Europe (EU; United-Kingdom, France, Spain, Germany, Italy) and 60 in Latin America (LATAM; Mexico, Colombia). They completed demographic and clinical questionnaires as well as the FISQ-RMS for 7 consecutive days. The FISQ-RMS assesses fatigue symptoms, with a severity rated based on the mean of the 7-day symptom assessment, and its impact on 3 domains: physical, cognitive/emotional and coping. The FISQ-RMS scores range from 0 to 100 (higher score indicates greater severity).

RESULTS: Respondents had similar demographic profiles across countries regarding gender (US: 88% women, EU: 86%, LATAM: 77%) and mean age (43 years). Almost all patients reported an impact of fatigue on their QoL (US: 93%, EU/LATAM: 90%). Most patients were not relapsing (US: 90%, EU: 88%, LATAM: 92%) during the FSIQ-RMS 7-day assessment period, yet they reported high levels of fatigue with mean scores of 57.3 (US), 55.2 (EU) and 67.8 (LATAM) for the fatigue symptom domain. For the impact domains, the mean scores were 42.3 (US), 47.0 (EU) and 53.4 (LATAM) for physical, 43.4 (US), 42.2 (EU), 52.3 (LATAM) for cognitive/emotional and 50.1 (US), 51.5 (EU), 59.0 (LATAM) for coping.

CONCLUSIONS: Using an RMS specific tool, the FSIQ-RMS, this survey helped quantify the severe levels of fatigue experienced by a multi-country cohort of RMS patients, even outside of relapses.