Project Summary

This project is ongoing and does not have results.

The Patient-Centered Outcomes Research Institute (PCORI) is partnering with the Agency for Healthcare Research and Quality (AHRQ) to develop a systematic evidence review on Medical Care for Adults with Down Syndrome. The Global Down Syndrome Foundation (GLOBAL) nominated the topic to PCORI in anticipation of the systematic review informing a future guideline.


Down syndrome, a chromosomal condition in which individuals are born with an extra full or partial copy of chromosome 21, is the most prevalent genetic cause of intellectual disability. Down syndrome occurs in one out of every 700 live births in the United States, a rate that has risen over the past years from one in 1,000. This means that although an estimated 200,000 individuals with Down syndrome lived in the United States in 2010, adjusting for the rising birthrate suggests the population could far exceed 350,000.

Down syndrome is characterized by a host of disparate medical, psychological and social issues beyond intellectual disability, and individuals with Down syndrome face very different risks for many co-occurring health conditions compared with the general population. In the case of Alzheimer’s disease, for example, individuals with Down syndrome are at greatly increased risk, with a lifetime risk of up to 90 percent, and an earlier age of onset and mortality compared to those without Down syndrome. Increased risk is also apparent for a number of other conditions including thyroid disease, obstructive sleep apnea and diabetes. Conversely, individuals with Down syndrome experience a decreased risk for some other diseases, such as solid tumor malignancies and atherosclerotic cardiovascular disease.

The unique health issues and considerations for individuals with Down syndrome pose a challenge to providing high-quality, comprehensive medical care throughout their lifespan. The life expectancy for individuals with Down syndrome has significantly increased from past decades and is now at 60 years of age compared to just 25 years in the 1980s. Accordingly, there is an increased need for high-quality, long-term care to support healthy aging, manage co-occurring conditions and promote quality of life. However, a lack of funding and underrepresentation of individuals with Down syndrome in research has led to a lack of evidence on how best to manage the health and co-occurring conditions for this population.

As the number of individuals with Down syndrome grows and life expectancy continues to rise, the need to identify best practices for the medical management of adults with Down syndrome intensifies. In response to this need, the Global Down Syndrome Foundation (GLOBAL) published the 2020 clinical practice guideline, Medical Care for Adults With Down Syndrome, which is recognized as the first evidence-based guideline supporting clinicians caring for adults with Down syndrome. The guideline is cited by key clinical resources and organizations, including the National Institutes of Health, the Down Syndrome Medical Interest Group of the United States, the National Down Syndrome Congress and the National Down Syndrome Society. 

A new systematic review in support of guideline development is warranted, as evidence has accumulated in the past few years. Additionally, while a few recent systematic reviews offer insights for specific health conditions in this population, including the estimated prevalence of co-occurring conditions like osteopenia, and pharmacologic treatments for dementia, none comprehensively synthesize the evidence for adults with Down syndrome. Given the lack of a recent and comprehensive systematic review in the face of accumulating evidence, this proposed systematic review will aim to support an update of the GLOBAL guideline on medical care for adults with Down syndrome in order to inform decision making for physicians, patients and caregivers.

Proposed Key Questions (KQs)

KQ 1: What are the benefits and harms of screening/diagnostic interventions for co-occurring medical conditions in adults with Down syndrome?

KQ 2: What are the benefits and harms of interventions to treat co-occurring medical conditions specifically in adults with Down syndrome?

Proposed Contextual Questions (CQs)

CQ 1: What conditions occur more frequently in adults with Down syndrome and what is their prevalence compared to the general adult population. How does this vary by age/decade of age, gender, setting (rural), and race/ethnicity?

CQ 2: How do clinical symptoms and the presentation of common mental health conditions such as anxiety and depression differ among adults with Down Syndrome compared to their presentation in the general adult population?

More on This Project

Project Information

Agency for Healthcare Research and Quality (AHRQ)

Key Dates

September 2025


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Award Type
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Last updated: April 22, 2024