Clinical characteristics and impact on patient-reported outcomes and quality of life of people with ambulatory secondary progressive multiple sclerosis: DISCOVER study

Background: People with secondary progressive multiple sclerosis (pwSPMS) experience increasing disability, which impacts negatively on their health-related quality of life (HRQoL). Our aims were to assess the impact of secondary progressive multiple sclerosis (SPMS) on functional status and HRQoL and describe the clinical profile in this population. Methods: DISCOVER is an observational, cross-sectional, multicenter study with retrospective data collection in real-world clinical practice in Spain. Sociodemographic and clinical variables, functional and cognitive scales, patient-reported outcomes (PROs), and direct healthcare, and non-healthcare and indirect costs were collected. Results: A total of 297 evaluable pwSPMS with a EDSS score between 3-6.5 participated: 62.3 % were female and 18.9% had active SPMS. At the study visit, 77% of them presented an Expanded Disability Scale Score (EDSS) of 6-6.5. Nearly 40 % did not receive any disease-modifying treatment. Regarding the working situation, 61.6 % were inactive due to disability. PROs: 99.3 % showed mobility impairment in EuroQoL-5 Dimensions-5 Levels, and about 60 % reported physical impact on the Multiple Sclerosis Impact Scale-29. Fatigue was present in 76.1 %, and almost 40 % reported anxiety or depression. The Symbol Digit Modalities Test was used to assess cognitive impairment; 80 % of the patients were below the mean score. Participants who presented relapses two years before and had high EDSS scores had a more negative impact on HRQoL. PwSPMS with a negative impact on HRQoL presented a higher cost burden, primarily due to indirect costs. Conclusions: PwSPMS experience a negative impact on their HRQoL, with a high physical impact, fatigue, cognitive impairment, and a high burden of indirect costs.