Hospitalizations in people with down syndrome across age groups: a population-based cohort study in Switzerland.

Background: People with Down syndrome suffer from multiple associated diseases. However, knowledge on rates and causes of hospitalizations is limited. Methods: This population-based cohort study used national hospital claims data in Switzerland between January 1, 2012 and December 31, 2020. Included were hospitalizations of people aged 0-90 years. People with Down syndrome were identified using ICD-10-GM code Q90 and were compared to the general population. The primary outcome was the hospitalization rate. Secondary outcomes were the primary reasons for hospitalizations, secondary diagnoses, and in-hospital outcomes. Analyses were stratified by three age groups: neonates and infants (0-12 months), children and adolescents (1-17 years), and adults (18-90 years). We calculated incidence rates, risk ratios (RR), and regression coefficients with corresponding 95% confidence intervals (CI). Findings: Among 9,992,538 hospitalizations, 5697 were identified for people with Down syndrome. Hospitalization rate for people with Down syndrome was highest in the first two years of life. In the total general population, it was highest in adults beyond 60 years. Primary reasons for hospitalization among people with Down syndrome were classified as diagnoses of the circulatory system (neonates and infants: RR 13.3 [95% CI 12.0-14.6], children and adolescents: RR 3.3 [95% CI 2.7-3.9]), and infectious diseases (adults: RR 4.0 [95% CI 3.7-4.2]). At birth, individuals with Down syndrome typically had an average of six diagnoses, a number that the general population reaches, on average, by the age of 69. People with Down syndrome experienced worse in-hospital outcomes, including longer stays in both the hospital and intensive care unit by a factor of 1.7 and a higher all-cause in-hospital mortality by an overall rate difference of 1.9%. Interpretation: The findings underscore the medical complexity of hospitalized people with Down syndrome and emphasize the need for a comprehensive, age-inclusive approach to improve in-hospital outcomes and anticipate emergency hospitalizations across age groups. Funding: Kantonsspital Aarau AG.