High healthcare costs among adults with intellectual and developmental disabilities: a population-based study

Objective — While it is generally accepted that adults with intellectual and developmental disabilities (IDD) use health services to a greater extent than the general population, there is remarkably little research which focuses on the costs associated with their healthcare. Using population based data from adults with IDD in Ontario, this study aimed to estimate overall healthcare costs, classify individuals into high and non-high cost categories, and describe differences in the demographics, clinical profiles and healthcare use patterns between these groups.

Design — A retrospective cohort study based in Ontario, Canada was conducted with the use of linked administrative health data.

Methods — A costing algorithm developed for the general population in Ontario was applied to estimate healthcare costs of adults with IDD under age 65 for 2009 and 2010. Individuals were categorized into two groups according to whether their total annual healthcare costs were amongst the highest decile in the general population. These groups were compared on demographic and clinical variables, and relative mean costs for six types of healthcare services in the two groups were computed. In addition, we computed the proportion of individuals who remained in the high cost group over two years.

Results — Among adults with IDD, 36% had annual healthcare expenditures greater than $2,610 CAD (top decile of all Ontario adults under 65). These individuals were more likely to be female, to be in the oldest age groups, to live in group homes, and to be receiving disability income support than individuals whose expenditures were below the high-cost threshold. In addition, they had higher rates of all the physical and mental health conditions studied. Greatest healthcare expenses were due to hospitalizations, especially psychiatric hospitalizations, continuing care/rehabilitation costs, and medication costs. The majority of individuals whose healthcare costs placed them in the high cost category in 2009 remained in that category a year later.

Discussion — Adults with IDD are nearly 4 times as likely to incur high annual healthcare costs than those without IDD. Individuals with IDD and high healthcare costs have unique health and demographic profiles compared to adults with IDD whose annual healthcare costs are below the high cost threshold. Attending to their healthcare needs earlier in their healthcare trajectory may be an opportunity to improve health and reduce overall healthcare costs. It is important that we explore how to best meet their needs. Models proposed to meet the needs of adults with high healthcare costs in the general population may not apply to this unique group.