Rare Diseases

Topic Spotlight


A rare disease is defined as one that affects fewer than 200,000 Americans. (FDA/Orphan Drug Act of 1983)


PCORI has funded 42 comparative clinical effectiveness research studies that aim to help patients and their caregivers make better-informed decisions about their options for treating rare diseases. (As of February 2024)


An estimated 25 million Americans are affected by a rare disease. (Centers for Disease Control)

Upcoming PCORI Funding Opportunity: Opens May 7, 2024

2023 PCORI Annual Meeting Breakout Session Spotlight

PCORI Rare Disease Research: Portfolio Highlights and Future Directions

Read more about this session

Rare Disease Day Spotlight

The KIDCARE Study: Exploring Treatment Strategies for Rare Pediatric Illness

February 29 is Rare Disease Day and the last day of National Heart Month! In recognition of heart disease and rare diseases, PCORI spotlights Kawasaki disease—a rare form of cardiovascular disease that mainly affects children.

Kawasaki disease can lead to dangerous inflammation of the arteries that bring blood to the heart. The cause of Kawasaki disease is unknown, and few studies have been performed to evaluate therapy for children with persistent symptoms despite treatment. 

Read about the PCORI-funded KIDCARE Study, which compared treatment approaches for this rare condition

Database Identifies Emerging Technologies, Innovations

PCORI’s Horizon Scanning Database offers healthcare decision makers findings about advancements in six key areas of interest: Alzheimer’s disease and other dementias, cancer, cardiovascular diseases, COVID-19, mental and behavioral health, and rare diseases. This database can be used by patients, care partners, and others to track advancements in care options.

View the Database

Providing Critical Information to the Rare Disease Community

Aliza Fink, DSc, MS — a member of the PCORI Advisory Panel on Rare Diseases — shares how patient-centered outcomes research and comparative clinical effectiveness research are conducted differently in rare diseases and their importance for patients and families in the rare disease community.

Conducting CER in the Rare Disease Space

Mathew J. Edick, PhD — chair of the PCORI Advisory Panel on Rare Disease and a father of a child with a rare disease — shares how comparative clinical effectiveness research (CER) differs from other types of healthcare research and its importance to rare disease communities.

Engaging Rare Disease Stakeholders in Research

Danielle Boyce, MPH, DPA — a member of the PCORI Advisory Panel on Rare Disease and a mother of a child with a rare disease — shares some tips on what to consider and how best to approach and engage members of the rare disease community in healthcare research.

Study Results that Support Better-Informed Decisions

Treating Pain in Adults with Sickle Cell Disease

Findings from a PCORI-funded study published in the Annals of Internal Medicine show promise for improving care of individuals living with sickle cell disease (SCD) in the United States, who historically have been underserved by the medical community. Researchers compared treatment for patients with uncomplicated vaso-occlusive crisis (VOC) in emergency rooms (ERs) and infusion centers.

VOC is the most prevalent SCD complication and causes acute, excruciating pain that most commonly is treated in ERs. Patients receiving care in infusion centers reported waiting less time — about half as long — for pain medicine than ER patients. They also were more likely to receive care adhering to guidelines for the management of acute pain and less likely to be admitted to the hospital.

Rare Disease Study Spotlights

Improving Discussions on Treatment Options for Lupus Nephritis

Jasvinder Singh, MD, MPH, at the University of Alabama at Birmingham, developed a decision aid under a PCORI-funded research award to help African-American and Hispanic patients have quality discussions with their clinicians regarding treatment options for lupus nephritis, a rare disease that affects young women. His team is now working to expand the decision aid’s use in clinical practice with a PCORI dissemination and implementation award.