Contributions to Racial Disparity in Mortality among Children with Down Syndrome

Alzheimer Dementia Among Individuals With Down Syndrome

Importance

With the advancement in administrative data as a research tool and the reliance on public health insurance for individuals with Down syndrome, population-level trends in Alzheimer dementia in this population are beginning to be understood.

Objective

To comprehensively describe the epidemiology of Alzheimer dementia in adults with Down syndrome in a full US Medicare and Medicaid sample.

Design, Setting, and Participants

This cohort study included 132 720 adults aged 18 years or older with Medicaid and/or Medicare claims data with an International Statistical Classification of Diseases and Related Health Problems code for Down syndrome. Data were collected from January 1, 2011, to December 31, 2019, and analyzed from August 2023 to May 2024.

Main Outcomes and Measures

The main outcome was prevalence of Alzheimer dementia in each calendar year and during the 9-year period. Alzheimer dementia incidence rates by calendar year and age and stratified for race or ethnicity as well as time to death after Alzheimer dementia diagnosis were also assessed.

Results

There were 132 720 unique adults with Down syndrome from 2011 to 2019: 79 578 (53.2%) were male, 17 090 (11.7%) were non-Hispanic Black, 20 777 (15.7%) were Hispanic, 101 120 (68.8%) were non-Hispanic White, and 47 692 (23.3%) had ever had an Alzheimer dementia diagnosis. Incidence was 22.4 cases per 1000 person-years. The probability of an incident Alzheimer dementia diagnosis over 8 years was 0.63 (95% CI, 0.62-0.64) for those entering the study between ages 55 to 64 years. Mean (SD) age at incident diagnosis was 54.5 (7.4) years and median (IQR) age was 54.6 (9.3) years. Mean (SD) age at death among those with Alzheimer dementia was 59.2 (6.9) years (median [IQR], 59.0 [8.0] years). The mean (SD) age at onset for the Hispanic group was 54.2 (9.2) years, 52.4 (7.8) years for the American Indian or Alaska Native group, and 52.8 (8.2) years for the mixed race groups compared with 55.0 (7.8) years for the White non-Hispanic group. For age at death, there were no differences by sex. The mean (SD) age at death was later for the White non-Hispanic group (59.3 [6.8] years) compared with the Hispanic group (58.5 [7.8] years), Native American group (57.8 [7.1] years), and mixed race group (58.2 [7.0] years).

Conclusions and Relevance

In this cohort study of adults with Down syndrome who were enrolled in Medicaid and Medicare, Alzheimer dementia occurred at high rates. Consistency with clinical studies of dementia in Down syndrome supports the use of administrative data in Down syndrome-Alzheimer dementia research.

Adherence to adult clinical practice guidelines for Down syndrome

Adults with Down syndrome (DS) have unique health care needs with evidence-based care guidelines to address these. Yet, the 2020 adult guidelines were unstudied; we aimed to assess adherence to these guidelines. We reviewed clinical and demographic data from medical charts of 327 adults with DS who were seen in the MGH DSP. We calculated adherence to care guidelines and analyzed correlations between both demographic traits and clinical results. Mean adherence rate to each of the nine adult guidelines was 67.3%. Adherence rates that were below our mean adherence rate included colonoscopy (42.9%), iron (41.9%), audiology specialist (35.8%), and audiogram (35.2%). We found four significant correlations: assigned females at birth had a significantly higher body mass index (BMI) than assigned males at birth (p < 0.001), Hispanic patients had a significantly higher BMI than other patients (p = 0.015), Hispanic patients had a significantly higher rate of diabetes than other patients (p = 0.036), and Black patients had a significantly lower rate of hypothyroidism than other patients (p = 0.004). We assessed the adherence rates to adult DS guidelines and highlighted disparities in healthcare for patients with DS to inform clinicians on how to improve care for patients with DS.

Occurrence of mosaic Down syndrome and prevalence of co-occurring conditions in Medicaid enrolled adults, 2016-2019

BACKGROUND

Mosaic Down syndrome is a triplication of chromosome 21 in some but not all cells. Little is known about the epidemiology of mosaic Down syndrome. We described prevalence of mosaic Down syndrome and the co-occurrence of common chronic conditions in 94,533 Medicaid enrolled adults with any Down syndrome enrolled from 2016 to 2019.

METHODS

We identified mosaic Down syndrome using the International Classification of Diseases and Related Health Problems, tenth edition code for mosaic Down syndrome and compared to those with nonmosaic Down syndrome codes. We identified chronic conditions using established algorithms and compared prevalence by mosaicism.

RESULTS

In total, 1966 (2.08%) had claims for mosaic Down syndrome. Mosaicism did not differ by sex or race/ethnicity with similar age distributions. Individuals with mosaicism were more likely to present with autism (13.9% vs. 9.6%) and attention deficit hyperactivity disorder (17.7% vs. 14.0%) compared to individuals without mosaicism. In total, 22.3% of those with mosaic Down syndrome and 21.5% of those without mosaicism had claims for Alzheimer's dementia (Prevalence difference: 0.8; 95% Confidence interval: -1.0, 2.8). The mosaic group had 1.19 times the hazard of Alzheimer's dementia compared to the nonmosaic group (95% CI: 1.0, 1.3).

DISCUSSION

Mosaicism may be associated with a higher susceptibility to certain neurodevelopmental and neurodegenerative conditions, including Alzheimer's dementia. Our findings challenge previous assumptions about its protective effects in Down syndrome. Further research is necessary to explore these associations in greater depth.

Down Syndrome: Evaluating Disparities in Place of Death in the United States Using Centers for Disease Control and Prevention's Wide-Ranging Online Data for Epidemiologic Research (CDC-WONDER) Database Over 22 Years

INTRODUCTION

The Uniform Determination of Death Act (UDDA) ensures that individuals with irreversible cessation of circulatory, respiratory, or brain functions receive timely palliative care. Our research has focused on identifying disparities in mortality among individuals with Down syndrome (DS) based on gender, age, racial groups, and geographic regions within the United States over 22 years. This study aims to analyze differences in the location of death, including hospitals, nursing homes, hospice care facilities, and unspecified locations, considering demographic and regional variables.

METHODOLOGY

Utilizing a cross-sectional observational study design, we extracted data from the Centers for Disease Control and Prevention's Wide-ranging Online Data for Epidemiologic Research (CDC-WONDER) database, specifically targeting deaths coded under the International Classification of Diseases, 11th Revision (ICD-11) code "Q-90." This analysis, covering 1999 to 2020, segmented the data by age, gender, race, and United States Census regions. Death locations were categorized into home/hospice, medical facilities, and nursing/other facilities. Data analysis was conducted using Microsoft Excel, and the Autoregressive Integrated Moving Average (ARIMA) model was applied for statistical assessments.

RESULTS

Our analysis included 22604 deaths related to DS, as recorded in the CDC-WONDER database from 1999 to 2020. The majority of these deaths occurred in medical or nursing facilities, with home or hospice deaths accounting for 6106 cases and other locations for 5.29% of deaths. Univariate logistic regression was used to identify predictors of home or hospice deaths, revealing a trend of increasing deaths in these settings over time.

CONCLUSIONS

Between 1999 and 2020, there was a notable increase in the number of individuals with DS dying at home or in hospice care, especially among those aged 55-64. Female individuals and those identified as white experienced higher mortality rates than other demographic groups. This shift highlights the need to understand the disparity in places of death within this population, ensuring equitable access to quality end-of-life care for all individuals with DS.

The National Institutes of Health INvestigation of Co-occurring conditions across the Lifespan to Understand Down syndromE (INCLUDE) Project: Accelerating research discoveries for people with Down syndrome across the lifespan

The National Institutes of Health (NIH) has a long-standing history of support for research in Down syndrome (DS). In response to a 2018 congressional directive for a trans-NIH initiative to address medical issues in DS, NIH launched the INCLUDE Project (INvestigation of Co-occurring conditions across the Lifespan to Understand Down syndromE). Reflecting the three INCLUDE components of basic science research, cohort development, and clinical trials, the Project has published funding opportunities to address conditions such as immune disorders and Alzheimer's disease. Due to a steady expansion in dedicated funding over its first 5 years, INCLUDE has invested $258 M in over 250 new research projects. INCLUDE also supports training initiatives to expand the number and diversity of investigators studying DS. NIH has funded an INCLUDE Data Coordinating Center that is collecting de-identified clinical information and multi-omics data from research participants for broad data sharing and secondary analyses. Through the DS-Connect® registry, INCLUDE investigators can access recruitment support. The INCLUDE Research Plan articulates research goals for the program, with an emphasis on diversity of research participants and investigators. Finally, a new Cohort Development Program is poised to increase the impact of the INCLUDE Project by recruiting a large DS cohort across the lifespan.

Caregivers' perception of adults with Down syndrome willingness to participate in research

BACKGROUND

Historically, individuals with Down syndrome have been excluded from clinical research. Our objective was to assess the degree of interest adults with Down syndrome have in participating in research from the perspective of the caregivers who care for them.

METHODS

We conducted an online survey of N = 390 caregivers of adults with Down syndrome and asked about interest in research participation and demographics.

RESULTS

Caregivers were mostly family members, older than 55 years, and White. Caregivers reported that the adult with Down syndrome that they cared for would be more comfortable participating in research that was physiological, such as research involving fit bits (70.2% would participate), exercise (63.3%) or diet apps (53.9%), whereas they would be less likely to participate in clinical trials involving more invasive procedures such as injections (10.9%) and laboratory exams like MRIs (32.0%). We found little difference by age or gender of the adult with Down syndrome or by caregiver education level.

CONCLUSIONS

Our survey identified high interest for less invasive studies, illustrating acceptability of observational and lifestyle studies. More effort may be needed to understand fear and barriers to participation and to create tools and methods to increase interest in more invasive studies.

Sleep Apnea in Children With Down Syndrome

OBJECTIVE

The authors of this study aimed to evaluate the use of polysomnography (PSG) in children with Down syndrome (DS) between ages 0 and 7 years, to assess the prevalence and severity of obstructive sleep apnea (OSA) and associated comorbidities, and to describe interventions used for OSA.

METHODS

A retrospective cohort study was performed at Cincinnati Children's Hospital Medical Center for children with DS born between 2013 and 2019. Data were extracted from the electronic medical record, including demographics, age at PSG, PSG results, and interventions after an abnormal PSG. Statistical analysis included unadjusted bivariate association testing and multivariable logistic regression modeling to investigate associations with OSA severity.

RESULTS

Among 397 patients in the cohort, 59% (n = 235) had a documented PSG and 94% (n = 221) had an abnormal study with 60% (n = 141) demonstrating moderate or severe OSA. There was an inverse relationship between age and OSA severity (P < .001). In a multiple regression model, OSA severity was associated with increased rates of failure to thrive (P < .01), aspiration (P = .02), and laryngomalacia (P < .01). After medical or surgical intervention, 73% of patients experienced the resolution of OSA or an improvement in OSA severity.

CONCLUSION

In this study of pediatric patients with DS, OSA was identified most frequently in the first year of life. In addition, to prompt evaluation of symptomatic infants, our data support earlier PSG screening for patients requiring neonatal ICU care and those with feeding difficulties, airway abnormalities, and/or pulmonary hypertension given their increased risk for severe OSA.

Review of epidemiological factors (other than maternal age) that determine the prevalence of common autosomal trisomies

The birth prevalence of each common autosomal trisomy (21, 18 and 13) increases with advancing maternal age and this is the most important epidemiological risk factor. Prevalence during pregnancy is also dependent on gestational age. Other factors claimed to influence prevalence include paternal age, ethnicity, family history, premature reproductive aging, parity, twinning, smoking, environmental exposures, maternal medical conditions, and predispositions. We review the evidence for these associations since they may provide insights into causal mechanisms. When investigating potential co-factors it is important to adequately allow for maternal age and minimize its confounding contribution. This is well illustrated by reports of an inverse paternal age effect where there is strong correlation between parental ages. Gestational age at diagnosis, availability of prenatal screening, diagnostic testing, and elective termination of affected pregnancies and healthcare disparities also confound the studies on ethnicity, medical conditions, and predispositions or environmental factors. Data from twin zygosity studies demonstrate the importance of differences in fetal viability for affected pregnancies. We conclude that existing epidemiological evidence for most of the co-factors discussed should currently be considered tenuous; history of Down syndrome, albeit biased, may be an exception. The co-factors may yet provide clues to hitherto poorly understood causal pathways.

Demographic and Clinical Characteristics Associated With Adherence to Guideline-Based Polysomnography in Children With Down Syndrome

OBJECTIVES

To compare the demographic and clinical characteristics of children with Down syndrome who did and did not receive polysomnography to evaluate for obstructive sleep apnea after publication of the American Academy of Pediatrics' guidelines recommending universal screening by age 4 years.

STUDY DESIGN

Retrospective cohort study.

SETTING

Single tertiary pediatric hospital.

METHODS

Review was conducted of children with Down syndrome born between 2007 and 2012. Children who obtained polysomnography were compared with children who did not, regarding demographic data, socioeconomic status, and comorbidities.

RESULTS

We included 460 children with Down syndrome; 273 (59.3%) received at least 1 polysomnogram, with a median age of 3.6 years (range, 0.1-8.9 years). There was no difference in the distribution of sex, insurance status, or socioeconomic status between children who received polysomnography and those who did not. There was a significant difference in race distribution (P = .0004) and distance from home to the medical center (P < .0001) between groups. Among multiple medical comorbidities, only children with a history of hypothyroidism (P = .003) or pulmonary aspiration (P = .01) were significantly more likely to have obtained polysomnography.

CONCLUSIONS

Overall, 60% of children with Down syndrome obtained a polysomnogram. There was no difference between groups by payer status or socioeconomic status. A significant difference in race distribution was noted. Proximity to the medical center and increased medical need appear to be associated with increased likelihood of obtaining a polysomnogram. This study illustrates the need for improvement initiatives to increase the proportion of patients receiving guideline-based screening.

Trends and predictions for survival and mortality in individuals with Down syndrome in Brazil: A 21-year analysis

BACKGROUND

Regional heterogeneities and sociodemographic characteristics affect mortality and population survival in Brazil. However, for individuals with Down syndrome (DS) this information remains unknown. In this study, we analysed survival and mortality rates among DS individuals in the five Brazilian geographic regions. In addition, we investigated whether there is an association between mortality and sociodemographic factors across administrative regions.

METHODS

Data between 1996 and 2016, comprising 10 028 records of deaths of individuals with DS, were collected from database records of the Department of Informatics of the Unified Health System. Data on race/ethnicity, sex, age and years of schooling were defined for the association analyses. Survival data were analysed according to the Kaplan-Meier method and Cox regression model.

RESULTS

The number of deaths among people with DS has increased in recent years. Children are more susceptible to death, especially in the first years of life. Individuals living in the northern region, Indigenous women and people with no years of schooling have higher mortality. In the Southeast and South region, for White and Yellow, survival is related to a higher level of education. Ethnic factors and years of schooling influence risk for mortality across the administrative regions.

CONCLUSIONS

These findings show that sociodemographic characteristics affect survival and are associated with the risk of mortality for people with DS. In addition, this suggests that differences in access to health services among Brazilian regions, especially in the first years of life, may affect the survival of individuals with DS.