Preface to the AHRQ Supplement

Excerpt

According to a 2010 Institute of Medicine (IOM) report,1 an estimated 5,000 to 8,000 diseases are categorized as rare and together affect millions of Americans. While some rare diseases have a very small patient population, others affect many thousands of people in the United States and worldwide. As the IOM report states, “rare diseases are not rare, at least in the aggregate”1 and are responsible for an enormous impact on the lives of patients, their families, and health care systems. For many rare diseases, there are no diagnostic tests or treatments; and there is a lack of basic knowledge about their natural history, diagnosis, and how best to provide health care to those who are affected. Yet, for other rare diseases, despite the growing number of diagnostic tests and treatment options, we have insufficient evidence on their long-term effects, comparative effectiveness, and safety. Often research is also limited in its ability to assess how health care delivery affects patient outcomes or how medical practice can be improved to address the unique needs of patients living with rare diseases. The importance of outcomes research for rare diseases was recognized in the initial national priorities for comparative effectiveness research2 and in the Patient Protection and Affordable Care Act, which required the Patient-Centered Outcomes Research Institute to appoint an expert advisory panel for rare disease research. …