The relation between Down syndrome and co-occurring conditions in children and young adults: A population-based cohort in Denmark, 1977-2016.
Down syndrome brings a lifetime stack of medical risks—build proactive health screens into ABA programs.
01Research in Context
What this study did
Yin et al. (2025) tracked every person with Down syndrome in Denmark for 30 years. They used national medical records to count how often heart, lung, eye, immune, and other problems show up.
The cohort covered births from 1977 to 2016. The team compared rates to the rest of the Danish population.
What they found
People with Down syndrome carry far higher lifetime risk of many medical issues. Heart defects, thyroid disease, hearing loss, and pneumonia all appeared far above general-population levels.
The data give behavior analysts a clear map of what health problems to watch for.
How this fits with other research
Gandhi et al. (2022) zoomed in on Welsh infants and found the same pattern earlier: babies with Down syndrome land in hospital sooner, stay longer, and are readmitted more often. Cheng's 30-year view shows those early stays are the first step of a lifelong trend.
Laposa et al. (2017) tested hearing in 72 adults and reported two-thirds had measurable loss, climbing to 90 % after age 50. Cheng's registry confirms hearing loss is one of the top chronic conditions across the whole Danish cohort.
Capio et al. (2013) showed that adults who had not fully switched from pediatric to adult doctors cost the system more and saw more specialists. Cheng's paper supplies the medical reason: this group carries a long list of hidden conditions that keep flaring up.
Why it matters
Build medical check-ins into every behavior plan. Schedule cardiac follow-ups, thyroid labs, and audiology before you see signs. Use the high comorbidity list when writing treatment goals or justifying authorizations—reviewers now have national data showing these clients need integrated care.
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02At a glance
03Original abstract
BACKGROUND AND OBJECTIVE: Recognizing the common co-occurring conditions among individuals with Down syndrome (DS) is essential for maintaining appropriate screening and optimizing healthcare resources. However, many previous studies relied on hospital- or community-based convenience samples with small sample sizes, limiting their generalizability. This study aimed to investigate the association between DS and co-occurring conditions in a large cohort of children and young adults. METHODS: We conducted a population-based retrospective cohort study using Danish national registers. The cohort had 1779912 participants born from 1977 to 2013 including 1385 with DS. For congenital conditions, we estimated inverse-probability-weighted (IPTW) absolute prevalence and prevalence difference. Time to event analyses (proportional hazard regression and IPTW cumulative incidence function estimation) were utilized to estimate the association between DS and risk for non-congenital co-occurring conditions. Sub-analyses examined risks among individuals with leukemia and sex-specific differences. RESULTS: Analyses showed very large prevalence ratios for many congenital conditions, including atrioventricular septal defects (PD=0.181, 95 % CI: 0.162, 0.203; PR=489, 95 % CI: 425-562), atrial septal defects (PD=0.215, 95 % CI: 0.194, 0.238; PR=94, 95 % CI: 84-105), and tetralogy of Fallot (PD=0.020, 95 % CI: 0.014, 0.029; PR=67, 95 % CI: 45-99). Individuals with DS had higher risks for cardiovascular disorders: pulmonary hypertension (HR=103.44, 95 % CI: 71.26-150.15), and stroke (HR=6.50, 95 % CI: 3.09-13.65). Additionally, the diagnosis was associated with increased risks of autoimmune diseases including celiac disease (HR=14.03, 95 % CI: 10.65-18.49) and type 1 diabetes (HR=3.40, 95 % CI: 2.08-5.54). Positive associations were also found for cerebral palsy (HR=9.77, 95 % CI: 7.32-13.06), and respiratory failure (HR=12.97, 95 % CI: 9.30-18.10). At 30 years of follow-up, IPTW absolute risks illustrated the clinical burden: e.g., pulmonary hypertension (AR1=0.028 vs AR0=0.0002, RD=0.026, RR=138.50), keratoconus (AR1=0.025 vs AR0=0.006, RD=0.025, RR=43.19), and respiratory failure (AR1=0.034 vs AR0=0.002, RD=0.031, RR=13.98). DISCUSSION AND CONCLUSION: Individuals with DS have notably higher risks of many co-occurring conditions. Our findings suggest that attention should be given to the management of autoimmune and ophthalmologic conditions, particularly regarding their incidence patterns over time and by gender.
Research in developmental disabilities, 2025 · doi:10.1016/j.ridd.2025.105167