Abstract
INTRODUCTION: Critical gaps exist in the understanding of the continuum of multiple sclerosis (MS) progression, particularly with regard to the patient experience prior to and during the transition from relapsing-remitting MS (RRMS) to secondary-progressive MS (SPMS) stages. To date, there are no clear diagnostic criteria in the determination of the clinical transition. We report here the use of patient experience data to support the development of a qualitative conceptual model of MS that describes the patient journey of transition from active-relapsing disease to progressive MS. METHODS: The study used a single-encounter, multicenter, qualitative observational study design that included a targeted literature review and individual, in-depth interviews with adult patients with a clinically confirmed diagnosis of SPMS and their adult care partners. Descriptions of symptoms and impacts of RRMS and SPMS were extracted from the literature review and used to support development of the interview guide and conceptual model. RESULTS: Participants described a slow progression in terms of change in symptoms over time, including both the development of new symptoms and the worsening of existing symptoms. CONCLUSIONS: The conceptual model of the transitionary period from RRMS to SPMS expands the current understanding of the progression of MS from the patient and care partner perspectives.