Prevalence of sensory impairments, physical and intellectual disabilities, and mental health in children and young people with self/proxy-reported autism: Observational study of a whole country population.

This study investigated the comorbid conditions in a whole country population of children/young people aged 0-24 years with and without autism. Data were drawn from Scotland's Census 2011. We calculated the percentage with autism, their extent of comorbid conditions, odds ratio (with 95% confidence intervals) of autism predicting comorbidities, adjusted for age and gender, and odds ratio for age and gender predicting comorbidities within the cohort with autism. A total of 25,063/1,548,819 (1.6%) had autism: 19,880 (79.3%) males and 5183 (20.7%) females. Autism had an odds ratio of 5.4 (5.1-5.6) for predicting deafness/partial hearing loss, odds ratio of 8.9 (8.1-9.7) for blindness/partial sight loss, odds ratio of 49.7 (38.1-64.9) for intellectual disabilities, odds ratio of 15.7 (13.4-18.5) for mental health conditions, odds ratio of 15.8 (14.1-17.8) for physical disability and odds ratio of 3.9 (3.8-4.0) for other conditions. Females with autism were more likely to have each additional condition than males, including intellectual disabilities, suggesting they may have more severe autism than males and adding evidence that autism may be currently underdiagnosed in more intellectually able females. These conditions are disabling and have a significant impact on long-term quality of life; their coexistence with autism adds extra complexity. It is important to raise clinicians' awareness of this extent of comorbidity, and to have accurate prevalence data to plan prevention and intervention measures, and to follow health inequality trends.