Accessible, up-to-date information on traumatic brain injury (TBI) can be challenging to find and is needed to address TBI knowledge gaps and improve outcomes for people who experience a TBI. The Understanding TBI Massive Open Online Course (TBI MOOC) was developed to increase TBI knowledge across a diverse global audience. We sought to characterize the TBI MOOC participant cohort, to understand the reach of the course among this target audience. Examining the characteristics of TBI MOOC enrollees showed that participants came from a wide range of demographic backgrounds, had a variety of TBI experiences and had multiple reasons for enrolling in the MOOC. The majority of course participants shared some characteristics with other groups of health information seekers. Four distinct demographic profiles were identified among TBI MOOC participants (education seekers, TBI-aware participants, TBI care providers and retirees) using a novel approach combining chi-squared tests and network modularity. Participants assigned to the TBI-aware and retiree profiles were most likely to complete all modules of the MOOC, and the TBI-aware profile was more highly represented in more recent iterations of the MOOC. Together, these data indicate that the TBI MOOC provided information to a wide range of people, and particularly engaged participants with personal or family experience of TBI. However, engagement with this course was minimal among some hard-to-reach populations, including men and people with low levels of education, indicating that additional strategies are needed to ensure equity in health promotion.
