Could people with intellectual disabilities be discriminated against in economic evaluations of health-related interventions?

Traditional methods used in economic evaluations reward interventions with big improvements in quality of life and survival. But how do they fare in contexts where obtaining large improvements may not be the primary aim of the interventions? This is likely to be the case for interventions for people with intellectual disabilities.

Measuring the effects of interventions for people with intellectual disabilities

Economic evaluations are used to determine which interventions bring the highest value for money in a healthcare system like the NHS. They are based on the concept of cost-effectiveness, which implies calculating and comparing the costs and benefits of alternative healthcare interventions. Calculating the benefits typically means estimating how well and how long people will live as a result of the interventions being tested.

However, this approach could underestimate the value of interventions where large gains in quality of life and life expectancy are not expected. For people with intellectual disabilities maintaining or even slightly improving health and quality of life may still be key.

To explore what the literature says on how the effects of interventions for people with intellectual disabilities can be measured in economic evaluations, the MIDAS Theme in the ARC North West Coast has recently undertaken a new systematic review.

Intellectual disabilities: what are they?

In our systematic review we used the definition from the American Association on Intellectual and Developmental Disabilities which explains intellectual disabilities in terms of an individual’s limitations in both intellectual functioning and adaptive behaviour. Another definition, provided by Mencap, adds more details:

“A learning disability* is a reduced intellectual ability and difficulty with everyday activities – for example household tasks, socialising or managing money – which affects someone for their whole life. People with a learning disability tend to take longer to learn and may need support to develop new skills, understand complicated information and interact with other people”

Having an intellectual disability is often associated with other conditions, such as Down syndrome, autism, epilepsy, and cerebral palsy. In the UK alone, 1.5 million people have an intellectual disability (approximately 2% of the UK population) (Mencap, 2022); of these, roughly 350,000 are children or adolescents. The prevalence of intellectual disabilities calls for using appropriate methods to determine the cost-effectiveness of the interventions for this population. Not doing so would increase the risk of underestimating the value of these interventions, and could indirectly discriminate against people with intellectual disabilities.

Economic evaluations need a tailored approach to intellectual disabilities

From our review we found evidence-based solutions to challenges in economic evaluations of interventions for people with intellectual disabilities.

1. Interventions for people with intellectual disabilities are likely to have multiple impacts, which extend beyond the health and quality of life of the individual to those of their caregivers and family members.

To capture these multiple impacts, economic evaluations should consider adopting a wide perspective and considering any spillover effects.