INTRODUCTION: Multiple sclerosis (MS) is a disabling disease with unpredictable clinical manifestations. As clinical assessments may not fully capture the impact of MS on quality of life, they can be complemented by patient-reported outcome (PRO) measures to provide a more comprehensive picture of MS disease state and impact. The objectives of this study were to explore the experiences of people with relapsing-remitting MS, including symptoms and impacts on daily life, and to provide a conceptual model of MS outcomes. METHODS: A literature review of studies that evaluated the experiences of people with MS was completed and combined with semi-structured concept elicitation interviews conducted with 14 people with relapsing-remitting MS in the USA. RESULTS: The average age of the 14 participants was 43.9 (range 25-64) years, most were White (78.6%) and female (78.6%), and the mean duration since diagnosis was 6.6 (2-10) years. The most bothersome symptoms identified included fatigue (n = 9), cognitive dysfunction (n = 5), mobility/difficulty with walking (n = 3), and vision problems (n = 3). The most commonly reported impacts on daily life were balance problems/instability (n = 13), work life/productivity (n = 12), difficulty walking (n = 11), daily activities/household chores (n = 11), and leisure activities (n = 10). CONCLUSION: There was a high frequency of concepts associated with physical function, fatigue, and sensory-motor actions. A conceptual model was developed that captures the disease symptoms, impairments, and impacts identified in the interviews as well as known processes and symptoms identified in the literature search. This model underpins the appropriateness of PRO instruments, such as the PROMIS Fatigue (MS) 8a and PROMIS Physical Function (MS) 15a, which evaluate symptoms and impacts that matter most to people with MS.
