A novel disease specific scale to characterize the symptoms and impacts of fatigue in US adults with relapsing multiple sclerosis: A real-world study.

BACKGROUND

Fatigue is among the most frequent and disabling symptoms in patients with relapsing multiple sclerosis (RMS).

OBJECTIVE

To measure MS fatigue and its impact on daily life in a real-world US population using an MS-specific patient-reported outcome (PRO) instrument, the Fatigue Symptoms and Impacts Questionnaire-RMS (FSIQ-RMS).

METHODS

This ongoing prospective study recruited RMS patients from an online patient community (Carenity) across US. Baseline assessment data are reported. Participants completed questionnaires, including the 20-item FSIQ-RMS questionnaire, with the first seven symptom-related items collected daily for seven days, and the other 13 items on the seventh day assessing impacts of fatigue. The FSIQ-RMS scores range from 0 to 100 (higher score=greater severity). The impact of fatigue on several aspects of patients' lives was rated from 0 (no impact) to 10 (very high impact). Data on disease history, disease status, sleep, social and emotional functioning were also captured. Baseline assessment data of 300 RMS patients are reported while follow-up assessments up to 18 months are planned.

RESULTS

300 RMS participants completed the 7-day assessment (mean age 43.0 years, 88% women). Fatigue was rated as severe, with a mean score of 57.3 for the FSIQ-RMS symptom domain; 3 impact sub-domain scores were 42.3, 43.4 and 50.1 (physical, cognitive/emotional, and coping). Participants who were not in relapse (78%) reported less severe fatigue than those in relapse (22%): mean±SD symptom score of 54.6 ± 17.8 vs. 67.0 ± 19.7, p< 0.001. Fatigue had a higher intensity among those with depression than without (49% vs. 51%, with mean ± SD symptom score of 62.8 ± 16.9 vs. 52.1 ± 19.3, p< 0.001), and among those with sleep disorder than without (27% vs. 73%, 61.2 ± 19.2 vs. 55.9 ± 18.6; p< 0.05). The most common factor associated with increased fatigue was heat exposure (82%). Most participants (52%) reported experiencing fatigue before their MS diagnosis.

CONCLUSION

Fatigue influences daily functioning for most patients with RMS. The FSIQ-RMS is a novel and MS-specific PRO measure that can advance the understanding and management of fatigue.