26725
Identifying Associations Among Medical Comorbidities in Autism Spectrum Disorder.
Much research has documented high rates of co-morbid medical conditions in children with autism spectrum disorders. This includes speech disorders, developmental delay, ADHD, hypotonia, seizure disorder, sleep disorders, anxiety, disruptive behavior, gastro-intestinal disorders such as constipation and feeding difficulties, pica, and eczema. Less is known about whether these commonly co-exist in the same children.
Objectives:
To determine clinically meaningful and statistically significant associations among co-occurring medical conditions in children with ASD that, if identified, could lead to better identification, treatment or understanding of the disease process.
Methods:
The Autism Speaks-Autism Treatment Network Registry includes over 7,000 well-phenotyped children with ASD. From the registry, we studied 2114 children between the ages of 17 months to 5 years old and 1221 children 6-17 years old at 20 sites. Diagnoses and problems were reported by clinicians upon subject enrollment, and were grouped into 12 core problems. We determined the observed prevalence (O) of co-occurring conditions and estimated the expected prevalence (E) across the network, adjusting for site variability in the prevalence of individual conditions. We used O/E rather than the relative risk, since O/E is invariant to the ordering of the conditions, whereas the relative risk depends on whether one is estimating relative risk for condition 2 given condition 1 or condition 1 given condition 2. P-values were calculated using a Cochran-Mantel-Haenszel test stratified by site. Once calculations were completed, we identified pairs of conditions co-occurring more frequently than expected (O/E > 1) and highlight those differences which were statistically significant. We also identified pairs of conditions co-occurring less frequently than expected (O/E < 1), but because of the small number of individuals in such a pair these were less likely to be statistically significant (figures 1, 2).
Results:
Among the 66 condition pairs for each age group, we confirmed previously identified associations such as sleep disorders and anxiety symptoms in older children. We found associations not previously described: feeding with sleep disorders (younger children only), constipation with sleep disorders, feeding with speech disorders, and constipation with speech disorders.
Conclusions:
An understanding of medical problems that co-occur in children more frequently than would be expected, as identified through innovative statistical strategies, provides an opportunity to better screen for and treat conditions that could have a related etiology (i.e. sleep and constipation), and, thereby, improve quality of life for individuals with ASD. For example, while feeding problems are frequent in ASD, they are usually attributed to sensory issues with oral motor function less commonly considered. The association of feeding with speech disorders suggests oral motor problems may be more common than typically appreciated. The association of feeding with sleep disorders is clinically recognized but may indicate upper airway or oral motor dysfunction as is seen in obstructive sleep apnea, or could indicate underlying sensory or behavioral regulation issues that impact both feeding and sleep. Children with constipation may experience sleep disruption due to discomfort which could also contribute to feeding problems.