Designing Well-Being Intervention Trials for People With Progressive Multiple Sclerosis: The Importance of Understanding Usual Care Comparators.

Well-being captures an individual's capacity to lead a meaningful and engaged life. Interventions to address well-being go beyond managing symptoms or supporting daily activity performance. Designing trials to evaluate the effectiveness of such well-being interventions can be challenging. One such challenge is determining what the comparator or control arm should be. Several trials of complex interventions use usual care as a comparator, but this can be particularly challenging when planning trials across multiple countries and health care systems. Therefore, trial design decisions must be informed by a good understanding of what constitutes usual or routine well-being interventions across locations. Our international, multidisciplinary team's efforts to develop this understanding across our 8 countries found that efforts to support the well-being of people with progressive multiple sclerosis vary widely. This variability emphasizes the importance of having a consistent way to collect data and report on the components of usual well-being care to inform trial design.