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Research, Data and Outcomes Frequently Asked Questions

Why isn’t the survival data more current?

There are natural delays in collecting, reporting, and analyzing data. For example, the Center-Specific Survival Analysis provides survival at one year. This means that all patients must have had the opportunity to have lived for one year following their transplant. Then the data must be collected, validated, analyzed, and approved—a process which will take approximately an additional year.

For longer-term survival estimates, greater follow-up time is needed. To provide a valid estimate of three-year survival, at least half of the patients in the dataset must have had the opportunity to have lived for three years following their transplant. For example, to report on three-year survival statistics in 2015, at least half of included patients must have received their transplant before 2012.

Why can’t I get survival data for patients transplanted for a specific disease at a specific transplant center?

In most diseases, there are too few patients transplanted with any given disease at a single center to allow calculation of statistically meaningful survival data. Transplant is still a relatively rare procedure with fewer than 20,000 total autologous, related allogeneic and unrelated allogeneic transplants done each year in the U.S. For many diseases, there are fewer than 100 patients transplanted each year. When these small numbers are spread across more than 200 transplant centers, the number of patients transplanted at most centers is too small to accurately predict outcomes for patients with a particular disease at a specific center.

The Center for International Blood and Marrow Transplant Research® (CIBMTR) must also be aware of patient confidentiality when providing outcomes data for specific diseases at specific transplant centers. For some diseases that are very rare, there may be only one patient who receives a transplant at a center. Providing outcomes data for such diseases would reveal patient-sensitive information.

Transplant data are reported to the transplant outcomes registry of the C.W. Bill Young Cell Transplantation Program, also called the Stem Cell Therapeutic Outcomes Database. The transplant outcomes registry is managed under a Federal contract by Center for International Blood and Marrow Transplant Research® (CIBMTR).