Patient Experience in Early-Stage Parkinson's Disease: Using a Mixed Methods Analysis to Identify Which Concepts Are Cardinal for Clinical Trial Outcome Assessment.

Introduction: Qualitative research on patient experiences in early-stage Parkinson's disease (PD) is limited. It is increasingly acknowledged that clinical outcome assessments used in trials do not fully capture the range of symptoms/impacts that are meaningful to people with early-stage PD. We aimed to conceptualize the patient experience in early-stage PD and identify, from the patient perspective, those cardinal symptoms/impacts which might be more useful to measure in clinical trials. Methods: In a mixed-methods analysis, 50 people with early-stage PD and nine relatives were interviewed. Study design and results interpretation were led by a multidisciplinary group of patient, clinical, regulatory, and outcome measurements experts, and patient organization representatives. Identification of the cardinal concepts was informed by the relative frequency of reported concepts combined with insights from patient experts and movement disorder specialists. Results: A conceptual model of the patient experience of early-stage PD was developed. Concept elicitation generated 145 unique concepts mapped across motor and non-motor symptoms, function, and impacts. Bradykinesia/slowness (notably in the form of "functional slowness"), tremor, rigidity/stiffness, mobility (particularly fine motor dexterity and subtle gait abnormalities), fatigue, depression, sleep/dreams, and pain were identified as cardinal in early-stage PD. "Functional slowness" (related to discrete tasks involving the upper limbs, complex mobility tasks, and general activities) was deemed to be more relevant than "difficulty" to patients with early-stage PD, who report being slower at completing tasks rather than encountering significant impairment with task completion. Conclusion: Patient experiences in early-stage PD are complex and wide-ranging, and the currently available patient-reported outcome (PRO) instruments do not evaluate many early-stage PD concepts such as functional slowness, fine motor skills, and subtle gait abnormalities. The development of a new PRO instrument, created in conjunction with people with PD, that fully assesses symptoms and the experience of living with early-stage PD, is required. Plain Language Summary: We conducted research to find out about the experiences and symptoms that have the greatest impact on everyday living for people with early-stage Parkinson's disease. This research also looked at which symptoms patients think are important to be tracked in clinical trials. The research team running this study included people living with Parkinson's disease (called "patient experts"). The team also included technical experts and representatives of patient organizations. To begin with, people living with early-stage Parkinson's disease and relatives were interviewed. The interviews collected their thoughts on the impact of early-stage Parkinson's disease on their daily lives. These insights revealed which experiences and symptoms were most important. The research team analyzed ideas and quotes from the interviews to create a picture of early-stage Parkinson's disease. The symptoms that mattered the most to people living with early-stage Parkinson's disease were tremor, rigidity/stiffness, fatigue, depression, sleep/dreams, and pain. Another important symptom was slowness of movement (which is called "bradykinesia/slowness"), and in particular "functional slowness," which included tasks involving the upper limbs, complicated movement tasks, and general activities. Effects on mobility were also important, particularly fine motor skills and subtle walking abnormalities. This research shows the wide-ranging effects that early-stage Parkinson's disease has on patients from their perspective. It also shows which effects are important to capture in trials of therapies aimed at this patient group. [ABSTRACT FROM AUTHOR]