This systematic review of prevalence rates of chronic health conditions in children with intellectual disability found 2,994 relevant studies published between 1996 to 2008. 31 studies were included that the authors felt had sufficient methodological quality.
They found that the 6 most prevalent chronic health conditions were:
- Epilepsy (22.0/100),
- Cerebral palsy (19.8/100),
- Anxiety disorder (17.1/100),
- Oppositional defiant disorder (12.4/100),
- Down syndrome (11.0/100),
- Autistic disorder (10.1/100).
Not surprisingly, reported prevalence rates of chronic health conditions in children with intellectual disability were much higher than in the general population.
The authors add a note of caution however, as only a small number of studies were included in the review because of methodological problems in the primary sources and the number of chronic health conditions they reported on were limited.
Prevalence of Chronic Health Conditions in Children With Intellectual Disability: A Systematic Literature Review , Oeseburg B et al, in Intellectual and Developmental Disabilities, 49, 2, 59-85.