Traumatic Brain Injury Incidence in Adults with Intellectual and Developmental Disabilities

In Ontario, there are approximately 66,000 adults living with a diagnosis of intellectual and developmental disabilities (IDD). These individuals are nearly twice as likely to experience an injury compared to the general population. Falls are an important contributor to injuries in persons with IDD and in the general population, and are consistently found to be the leading cause of traumatic brain injury (TBI). There is currently no literature that quantitatively examines TBI among persons with IDD. The purpose of this study was to compare the risk of TBI for adults with and without IDD in Ontario over time and by demographic information.

Using administrative health databases, two main cohorts were identified: (1) adults with IDD, and (2) a random 10% sample of adults without IDD. Within each cohort, annual crude and adjusted incidence of TBI were calculated among unique individuals for each fiscal year from April 1, 2002 to March 31, 2017.

Over the 15-year study period, the average annual adjusted incidence of TBI was approximately 2.8 new cases per 1000 among Ontario adults with IDD, compared to approximately 1.53 per 1000 among those without IDD. In both cohorts, a higher proportion of TBI cases were younger (19-29 years) and male.

During the study period, persons with IDD experienced a significantly higher risk of TBI compared to the general population indicating the possibility, and need, for targeted TBI prevention.