Written and maintained by CASRAI Editorial Board
Last updated
Short answer (first 60 words)
The Scientific Registry of Transplant Recipients (SRTR) is the national clinical data registry and epidemiological analytics center evaluating solid organ transplantation in the United States. Mandated under the National Organ Transplant Act (NOTA) of 1984, SRTR aggregates data from the Organ Procurement and Transplantation Network (OPTN) and Medicare to evaluate program performance, survival outcomes, and support research.
Definition and scope
The Scientific Registry of Transplant Recipients (SRTR) is the independent national repository and statistical analysis center for solid organ transplantation. Established under the National Organ Transplant Act (NOTA) of 1984 and codified at 42 CFR § 121.11, SRTR is operated by the Chronic Disease Research Group (CDRG) of the Hennepin Healthcare Research Institute (HHRI) under contract from the Division of Transplantation, Health Resources and Services Administration (HRSA), U.S. Department of Health and Human Services (HHS).
The registry evaluates solid organ transplantation nationwide: candidate waitlisting, donor evaluations, allocation events, and post-transplant outcomes across kidney, liver, heart, lung, pancreas, intestine, and vascularized composite allografts. Unlike cancer registries focused primarily on disease staging, SRTR provides statistical modeling to evaluate allocation policies and supplies transplant programs and organ procurement organizations (OPOs) with standardized performance metrics.
How it works or how it is used in practice
SRTR harmonizes data through a multi-stream pipeline:
- OPTN UNet monthly extracts: The primary feed originates from the Organ Procurement and Transplantation Network (OPTN). Transplant centers, OPOs, and histocompatibility laboratories submit transactional candidate, donor, and recipient data into UNet. Each month, SRTR receives an OPTN database snapshot, including new registrations, transplants, follow-up forms, and historical corrections.
- NTIS Death Master File: Federal rules do not require living donor tracking beyond two years post-donation or follow-up on candidates removed without transplant. SRTR incorporates monthly updates from the National Technical Information Service (NTIS) Death Master File to capture mortality across all candidates and living donors.
- CMS administrative data: SRTR links Centers for Medicare & Medicaid Services (CMS) billing and End-Stage Renal Disease (ESRD) registry data to capture secondary graft failures, hospitalizations, and deaths outside the primary center.
- Special disease registries: SRTR supplements records with the National Cancer Institute (NCI) Transplant Cancer Match Study for post-transplant malignancies, pharmacy claims for immunosuppression adherence, and the Cystic Fibrosis Foundation registry.
From this pipeline, SRTR releases four core analytical products:
- Program-Specific Reports (PSRs): Semiannual evaluations released in January and July for each transplant program, assessing waitlist mortality, transplant rates, offer acceptance, and 1-year and 3-year risk-adjusted survival.
- OPO-Specific Reports (OSRs): Semiannual assessments evaluating each OPO on deceased donor yield and conversion ratios.
- OPTN/SRTR Annual Data Report: A national monograph published with the American Journal of Transplantation tracking multi-year trends in donation, waitlist size, and graft survival.
- Standard Analysis Files (SAFs): Quarterly releases of de-identified patient-level SAS datasets provided to independent research teams conducting observational study protocols and epidemiological modeling.
Types or related concepts
Navigating organ transplantation data requires distinguishing collaborating agencies under NOTA:
| Institution | Core Role | Governing Authority | Primary Outputs |
|---|---|---|---|
| SRTR | Statistical modeling, risk-adjusted performance evaluation, and research data release. | HRSA / HHS contract; NOTA of 1984; 42 CFR § 121.11 | Program-Specific Reports (PSRs), OPO-Specific Reports (OSRs), Annual Data Report, Standard Analysis Files (SAFs). |
| OPTN | Unified network setting allocation policies, candidate waitlists, and organ placement. | Federal mandate under NOTA; overseen by HRSA | National allocation algorithms, policy bylaws, clinical data standards. |
| UNOS | Non-profit contractor operating the OPTN infrastructure and matching services. | Contractor to HRSA / HHS | UNet platform administration, Organ Center 24/7 matching dispatch. |
| HRSA | Federal executive agency directing the Division of Transplantation; regulatory oversight. | U.S. Department of Health and Human Services | Federal contract administration, policy approvals, compliance enforcement. |
For researchers, SRTR structures Standard Analysis Files into four relational datasets linked through encrypted identifiers:
| SAF Component | Core Variables Included | Linkage Key | Research Application |
|---|---|---|---|
| Candidate Files | Listing date, urgency status history, clinical exceptions, CPRA scores, removal reasons. | Encrypted person ID (PERS_ID / PX_ID) | Waitlist mortality analyses, offer acceptance modeling, disparity studies. |
| Donor Files | Donor demographics, cause of death, clinical parameters, KDPI metrics, organ disposition. | Encrypted donor ID (DONOR_ID) | Donor yield evaluation, organ discard research, living donor tracking. |
| Transplant Files | Transplant date, HLA matching, crossmatch findings, ischemia times, immunosuppression. | Transplant record ID (TX_ID) | Immunogenetic compatibility research, graft function outcomes. |
| Transplant Follow-up Files | Clinical status, serum creatinine/eGFR, graft failure dates, patient death, malignancies. | Person ID and follow-up interval | Long-term graft survival modeling, chronic allograft failure studies. |
Where it matters for labs, clinics or supply decisions
SRTR data impacts clinical workflows, laboratory protocols, and research governance:
- Histocompatibility laboratories: Clinical immunology teams use SRTR data to evaluate human leukocyte antigen (HLA) matching and calculated panel reactive antibody (CPRA) thresholds. While the NMDP Registry facilitates marrow donor matching, SRTR provides longitudinal evidence linking donor-specific antibodies (DSA) and crossmatch protocols to graft survival.
- Transplant program monitoring: Centers use Program-Specific Reports for quality improvement. Because CMS and private payers review risk-adjusted outcomes during re-credentialing, clinical teams monitor offer acceptance rates and graft survival to evaluate organ acceptance patterns.
- Clinical research informatics: Researchers designing trials or integrating local REDCap research database workflows calibrate sample sizes against national SRTR incidence and survival estimates using standardized data dictionary definitions.
- Research data access protocol: Academic investigators access SRTR data under 42 CFR § 121.11 through three mechanisms:
- Simple information requests: Aggregated queries requiring under 2 hours of staff analysis time are provided free of charge via email.
- Complex data requests: Custom tabulations requiring over 2 hours of staff effort are billed at $125 per hour.
- Standard Analysis Files (SAFs): Researchers can request patient-level de-identified SAFs in SAS format ($1,000 initial; $500 per quarterly update). Requests require a research plan, human subjects review or exemption under informed consent guidelines, and an executed Data Use Agreement (DUA).
Common misunderstandings
Several misconceptions surround SRTR’s function within transplantation:
- Misunderstanding: SRTR allocates organs and manages the national waiting list.
Fact: SRTR plays no operational role in organ matching or waitlist dispatch. The Organ Procurement and Transplantation Network (OPTN) and UNOS manage UNet and coordinate organ allocation. SRTR is an evaluative body. - Misunderstanding: Center evaluations rely on unadjusted raw survival counts.
Fact: SRTR employs multi-variable risk-adjustment models adjusting for donor characteristics, recipient illness severity, and cold ischemic times to ensure fair comparisons. - Misunderstanding: SRTR datasets are restricted solely to federal contractors.
Fact: Under the OPTN Final Rule, SRTR releases data to any bona fide researcher whose project meets scientific standards and signs a Data Use Agreement. - Misunderstanding: Patients are lost to follow-up once they leave the reporting center.
Fact: Linking monthly records to CMS databases and the Social Security Death Master File captures patient deaths and graft failures across all institutions.
Frequently asked questions
What is the difference between SRTR and OPTN?
The Organ Procurement and Transplantation Network (OPTN) establishes organ allocation policy and manages candidate waitlists and real-time donor matching. The Scientific Registry of Transplant Recipients (SRTR) is the independent statistical contractor that analyzes OPTN data to evaluate clinical outcomes, publish center performance reports, and model policy changes.
How often are SRTR Standard Analysis Files updated?
SRTR releases updated Standard Analysis Files (SAFs) quarterly in March, June, September, and December, incorporating all historical data since October 1, 1987, alongside newly submitted records.
What file format is used for SRTR research datasets?
SRTR Standard Analysis Files are distributed exclusively in SAS format. Each delivery includes an electronic data dictionary outlining all variables, formats, and relational linkage keys across datasets.
How does SRTR adjust outcomes for patient illness severity?
SRTR uses hierarchical generalized linear models adjusting for donor and recipient risk factors—including age, diagnosis, functional status, life support requirements, and preservation times—to calculate expected survival rates against which observed outcomes are measured.
Sources
- Scientific Registry of Transplant Recipients (SRTR). “The SRTR Database.” Hennepin Healthcare Research Institute / HRSA. URL: https://www.srtr.org/transplant-professionals/reports/the-srtr-database/. Checked: November 8, 2026.
- Scientific Registry of Transplant Recipients (SRTR). “About SRTR Standard Analysis Files (SAFs).” Hennepin Healthcare Research Institute / HRSA. URL: https://www.srtr.org/requesting-data/about-srtr-standard-analysis-files-safs/. Checked: November 8, 2026.
- Scientific Registry of Transplant Recipients (SRTR). “Data Requests and Release Policy.” Hennepin Healthcare Research Institute / HRSA. URL: https://www.srtr.org/requesting-data/data-requests/. Checked: November 8, 2026.
- Scientific Registry of Transplant Recipients (SRTR). “Mission, Vision, and Values.” Hennepin Healthcare Research Institute / HRSA. URL: https://www.srtr.org/about-srtr/mission-vision-and-values/. Checked: November 8, 2026.
- Legal Information Institute, Cornell Law School. “42 CFR § 121.11 – Record maintenance and reporting requirements.” Electronic Code of Federal Regulations. URL: https://www.law.cornell.edu/cfr/text/42/121.11. Checked: November 8, 2026.
