Diagnostic patterns among people with intellectual disabilities compared to the general population (IDcare)

Background: People with intellectual disabilities (ID) often have an extensive and complex disease panorama. However, more knowledge is needed about the disease panorama to gain a deeper understanding of co-morbidity and potential care needs.

Methods: Among all people living in Skåne on January 1st, 2014, we established a cohort of 14 716 people with ID (either diagnosis of ID (F7) or Down Syndrome (Q90), or service and support for people with ID or autism spectrum disorder). After exclusion of those with a family member in the ID cohort, the general population (gPop) cohort comprised 1 232 299 people. Diagnoses on diseases (i.e., ICD-10 chapters I-XIV, excluding diagnoses of developmental disorders) were collected and compared between ID and gPop by age group.

Findings: There were both similarities and differences in the prevalence of disease for ID and gPop. E.g., for children, acute upper respiratory infections were the most common diagnosis diagnosed at least once during the study period in both cohorts, whereas disorders of ocular muscles, binocular movement, accommodation, and refraction were the second most common diagnosis registered at least once in ID (41% compared to 14% in gPop). Moreover, the difference in distribution of age-related diseases (e.g., Organic, including symptomatic, mental disorders, including dementia) between the ID and gPop cohort supports the hypothesis of earlier aging in ID.

Conclusions: When allocating resources for health care to vulnerable groups in society, it is important to acknowledge both differences and similarities in disease patterns with the general population. People with ID comprise a vulnerable group that is both different and alike their age peers in the general population. It is especially important to understand the earlier aging in this group, and its impact on health care needs.