Intellectual (Learning) Disability & associated conditions
*Note: The links below point to the modules in the Integrated Data Commons. If you do not have an account, please refer to the publicly viewable code module links here.
Background information
Intellectual disability is used to describe when a person has difficulty understanding, concentrating, learning and remembering new things in their everyday life. There are a number of different definitions of Intellectual Disability. The Intellectual Disability (Compulsory Care and Rehabilitation) Act 2003[1] defines an intellectual disability as a permanent impairment that:
- Results in an IQ of 70 or less
- Results in significant deficits in adaptive functioning in areas such as communication, self-care, home living, and social skills
- Becomes apparent before a person reaches the age of 18.
There are different types of intellectual disability and a spectrum of severity so that the support individuals require to live satisfying lives differs. Some people identified as having an intellectual disability also have a diagnosis of another associated condition. This module creates multiple tables including people with an intellectual disability and those with nine conditions that may be linked to intellectual disability. These associated conditions have been included as part of this module as there is some correlation between these conditions and intellectual disability. This does not mean however, that everyone with these conditions has an intellectual disability or vice versa. The code will allow researchers to better understand the overlaps between these conditions.
This module builds upon the analytical work of the IHC report From Data to Dignity: Health and Wellbeing Indicators for New Zealanders with Intellectual Disability (Kōtātā Insights, 2023). In addition to Intellectual Disability, this module also identifies individuals who have other diagnostically defined neurodevelopmental conditions. The table below presents the rate of diagnosis of intellectual disability, in descending order of comorbidity[2].
| Condition | Proportion of people identified with an intellectual disability diagnosis |
|---|---|
| Down syndrome | 44.2% |
| Fragile X syndrome | 41.3% |
| Cerebral palsy | 30.8% |
| Klinefelter syndrome | 22.9% |
| Fetal alcohol spectrum disorder (FASD) | 22.6% |
| Autism | 20.7% |
| Developmental delay | 16.5% |
| Attention deficit hyperactivity disorder (ADHD) | 13.6% |
| Spina bifida | 9.5% |
Data in the code module output tables is aggregated from a number of sources of diagnosis data or data (for example pharmaceutical use) that indicates a diagnosis is likely.
Code module links
Click on the links below to visit the respective code module pages:
- Intellectual (learning) disability
- Attention deficit hyperactivity disorder (ADHD)
- Autism
- Cerebral palsy
- Developmental delay
- Down syndrome
- Fetal alcohol spectrum disorder (FASD)
- Fragile X syndrome
- Klinefelter syndrome
- Spina bifida
Note:
When using these code modules it is important to make sure to consider biases and limitations of the IDI data as well as biases and limitations that exist within health/health-related datasets. Some biases may include under-diagnosis, miss-diagnosis, cultural preference, systemic racism, clinician bias, policy changes, and data recording changes. These biases and limitations will vary for different groups and therefore have different effects on the resulting data and any analysis.
www.ihc.org.nz/about-intellectual-disability/intellectual-disability ↩︎
See Table 5, section 3.2.1 Associated Conditions https://assets-global.website-files.com/628455c1cd53af649dec6493/6584cc68cbd28550e09d0397_Full_IDI%20report_final_web.pdf ↩︎