1 OVERVIEW AND HIGHLIGHTS

This Annual Data Report includes chapters on kidney, pancreas, liver, intestine, heart, and lung transplants, as well as chapters on deceased organ donation, vascularized composite allograft transplant, and COVID-19. The organ-specific chapters include information on such topics as the waiting list, deceased donor organ donation, living donor organ donation, transplant, outcomes, and pediatric transplant. When possible, similar data and formats are used for each chapter. However, this is not always possible because some data are not pertinent to all organs.

Graphical presentation of the data is emphasized: more than 600 figures (including any maps) and tables are included in the chapters. They may be copied and pasted from the HTML files into slides.

Maps in this report present data divided into quintiles. Figure 1 is a sample map.

Maps by donation service area (DSA) use DSA boundaries in effect at the beginning of 2021, after the merger of LifeChoice Donor Services and New England Organ Bank. Some DSAs include noncontiguous areas. If a DSA has no transplant program for a given organ or no listings during the map’s timeframe, it is labeled “No data” on the map and shaded accordingly.

Figure 1: Example map. In this example, about one-fifth of all data points have a value above 18.2. Ranges include the number at the lower end of the range and exclude that at the upper end (eg, the second range here is 9.3 to <12.4). Numbers in the first and last boxes are the minimum and maximum of observed data.

2 MILESTONE DATES IN THE PRODUCTION OF THIS REPORT

Data were cut: July 2022.

Data were analyzed: July 2022.

3 METHODS

cPRA
For recipients of kidney and pancreas transplants performed on January 1, 2010, or later, panel-reactive antibody (PRA) at the time of transplant is the calculated PRA (cPRA) value.

For recipients of heart transplants performed from January 1, 2010, through March 30, 2015, PRA at the time of transplant is the minimum value between the most recently recorded PRA and the peak PRA. For recipients of heart transplants performed on March 31, 2015, or later, the cPRA value was used at the time of transplant. If that value is missing, we use the peak cPRA value known at the time of transplant.

Heart status groups
Starting on October 18, 2018, adult candidates were allocated hearts based on status groups 1-6. Status 1 candidates have the highest waitlist mortality risk and status 6 the lowest. Before that date, candidates were allocated hearts based on status groups 1A (highest priority), 1B, and 2.

Incidence
Cumulative incidence of posttransplant outcomes (diabetes, posttransplant lymphoproliferative disorder, and acute rejection) are computed using survival methods.

Graft failure
Unless otherwise specified, “graft failure” refers to graft failure from any cause, including death and retransplant. For kidney failure, this also includes return to maintenance dialysis. “Graft survival” similarly refers to the absence of all-cause graft failure.

Patient survival
Posttransplant patient survival is not censored at graft failure. Thus, patient survival includes follow-up after graft failure, retransplant, and return to maintenance dialysis in the case of kidney recipients.

Transplant rates
Transplant rates include all waiting time (ie, active and inactive) in the interval described.

Pretransplant mortality
Pretransplant mortality rates include all waiting time, and patients are followed until the earliest date of transplant, death, transfer to another program, removal from the waiting list due to improved condition, or cohort censor date. Because we continue to follow candidates for death outcomes beyond removal (except removal due to improved condition), we do not include removal due to deteriorated condition as part of a combined outcome.

Rates by subgroup
When rates are shown by subgroup (ie, sex, race, or primary cause of disease), the numerator and denominator are computed exclusively within those groups. For example, for pretransplant mortality by race, the numerator for each race is the number of deaths in that group during the interval described. The denominator is the total waiting time within each race group in that same time interval. When a characteristic is subject to change over time (eg, model for end-stage liver disease [MELD], PRA), it is assessed at the earliest of transplant, death, removal, or December 31 of the year, and a candidate contributes waiting time and outcome only at that level. For example, age is assessed only once a year; therefore, a candidate contributes all of his or her waiting time to a single age category in a given yearly rate calculation but may change age categories over time. For example, a waitlisted candidate who was 34 years old on December 31, 2012, would be included in the 18- to 34-year age group in 2012, but if that candidate were still listed in 2014, he or she would be included in the 35- to 49-year age group.

Donor risk index
The kidney donor risk index (KDRI) and pancreas donor risk index (PDRI) are measures of donor quality based on donor factors.

\[ \begin{aligned} \text{KDRI}^1 = \exp(&-0.0194 \times [\text{if age} < 18 \text{yrs}] \times [\text{age}-18 \text{yrs}] +\\ &0.0128 \times [\text{age}-40 \text{yrs}] +\\ &0.0107 \times [\text{if age} >50 \text{yrs}] \times [\text{age}-50 \text{yrs}] +\\ &0.179 \times [\text{if African-American race}] +\\ &0.126 \times [\text{if hypertensive}] +\\ &0.130 \times [\text{if diabetic}] +\\ &0.220 \times [\text{serum creatitine}-1 \text{mg/dL}] -\\ &0.209 \times [\text{if serum creatinine} > 1.5 \text{mg/dL}] \times [\text{serum creatinine} - 1.5 \text{mg/dL}] +\\ &0.0881 \times [\text{if cause of death = cerebrovascular accident}] -\\ &0.0464 \times [(\text{height} - 170 \text{cm})/10] -\\ &0.0199 \times [\text{if weight} < 80 \text{kg}] \times [(\text{weight}-80 \text{kg})/5] +\\ &0.133 \times [\text{if DCD}] +\\ &0.240 \times [\text{if HCV+}])\\ \\ \text{PDRI}^2 = \exp(&-0.1379 \times [\text{if female}] -\\ &0.03446 \times [\text{if age} <20 \text{yrs}] \times [\text{age} -20 \text{yrs}] +\\ &0.02615 \times [\text{age} -28 \text{yrs}] +\\ &0.1949 \times [\text{if creatinine} > 2.5 \text{mg/dL}] +\\ &0.2395 \times [\text{if African-American}] +\\ &0.1571 \times [\text{if Asian}] -\\ &0.0009863 \times [\text{BMI} -24] +\\ &0.03327 \times [\text{if BMI} >25] \times [\text{BMI}-25] -\\ &0.006074 \times [\text{height} -173 \text{cm}] +\\ &0.2102 \times [\text{if cause of death = cerebrovascular accident}] +\\ &0.3317 \times [\text{if DCD}]) \end{aligned} \]

¹Rao PS, Schaubel DE, Guidinger MK, Andreoni KA, Wolfe RA, Merion RM, Port FK, Sung RS. A comprehensive risk quantification score for deceased donor kidneys: the kidney donor risk index. Transplantation. 2009;88(2):231-236. doi:10.1097/TP.0b013e3181ac620b

²Axelrod DA, Sung RS, Meyer KH, Wolfe RA, Kaufman DB. Systematic evaluation of pancreas allograft quality, outcomes and geographic variation in utilization. Am J Transplant. 2010;10:837-845. doi:10.1111/j.1600-6143.2009.02996.x

Complete versions of these indices also include transplant factors, but the donor-specific indices in this report are limited to donor-specific factors. Conversion of KDRI to a cumulative percentage scale (ie, KDPI) is done using the OPTN KDPI Mapping Tables. For donors with organs recovered January through May, the cohort 2 years prior was used to assign KDPI; for donors with organs recovered June through December, the cohort 1 year prior was used to assign KDPI. Kidneys recovered en bloc were counted once.

4 NOTES

Population reported
Figure titles indicate adult or pediatric populations; if not specified, data include patients of all ages. In the past, lung data included patients aged 12 years or older with adults, and figure titles specified the age ranges. Since the 2019 report, we have classified all lung patients aged 18 years or older as adults and younger patients as pediatrics.

Unless otherwise specified, data in each organ-specific chapter include both isolated transplants and multiorgan transplants of the given type. For example, patients on the kidney transplant waiting list include those listed for an isolated kidney, kidney-pancreas, or any other organ combination that includes kidney.

Waitlist populations are no longer reported at the person level. If a patient is listed at more than one center, that patient is counted once per listing.

Age
Adult patients are defined as those aged 18 years or older for all organs. For waitlist figures, age is defined at the time of first listing, unless otherwise specified.

Race and ethnicity
Multiracial patients are defined as other/unknown. When a given race is not shown, it is included with other/unknown.

Pancreas data
Pancreas data encompass the three types of pancreas waiting lists or transplants: simultaneous kidney-pancreas, pancreas after kidney, and pancreas transplant alone (ie, without kidney). Pancreata used for islet transplant are excluded.

MELD score
MELD scores shown in figures and tables are calculated MELD scores, not allocation MELD scores, unless otherwise specified.

Metropolitan and non-metropolitan designation
Many data are displayed by the designation of a candidate’s or recipient’s permanent zip code as metropolitan or non-metropolitan. We used rural-urban commuting area (RUCA) codes and defined metropolitan, micropolitan, small town, and rural areas. These were then collapsed into metropolitan areas, which include suburbs adjacent to major cities, and non-metropolitan, which include cities, towns, and rural areas of fewer than 50,000 people.

5 DATA REQUESTS

Requests for data can be made to SRTR at http://www.srtr.org or to OPTN at http://optn.transplant.hrsa.gov.

6 WEBSITES

http://www.srtr.org is a public website containing transplant program-specific reports, organ procurement organization (OPO)–specific reports, summary tables, archives of past reports, timelines for future reports, risk-adjustment models, methods, basic references for researchers who use SRTR data files, links to current and past Annual Data Reports and their supporting documentation and data tables, answers to frequently asked questions, and other information.

https://securesrtr.transplant.hrsa.gov is a secure website that provides access to the prerelease program- and OPO-specific reports, survival spreadsheets, and other useful information. All individual authorized users from transplant programs and OPOs have their own unique logins.

http://unos.org is a public website containing information on donation and transplant, data collection instruments, data reports, education materials for patients and transplant professionals, policy development, and other information. This website also links to the OPTN website.

http://optn.transplant.hrsa.gov is a public website containing news, information, and resources about transplant and donation, including transplant data reports, policy development, and related boards and committees. It also contains allocation calculators, a calendar of events, answers to frequently asked questions, and other information.

7 CONTACT INFORMATION

Research Inquiries
SRTR data requests: 877-970-7787 (toll free); srtr@srtr.org (email)

Media Inquiries
SRTR: 877-970-7787 (toll free); srtr@srtr.org (email)

Federal Program Inquiries
HHS/HRSA/HSB/DoT
5600 Fishers Lane
Parklawn Bldg, Eighth Floor West
Rockville, MD 20857
301-443-7577

8 COMMONLY USED ABBREVIATIONS IN THIS REPORT

This publication was produced for the U.S. Department of Health and Human Services (HHS), Health Resources and Services Administration (HRSA), by Hennepin Healthcare Research Institute (HHRI) and the United Network for Organ Sharing (UNOS) under contracts HHSH75R60220C00011 and HHSH250201900001C, respectively.

This publication lists nonfederal resources in order to provide additional information to consumers. The views and content in these resources have not been formally approved by HHS or HRSA. Neither HHS nor HRSA endorses the products or services of the listed resources.

The OPTN/SRTR 2021 Annual Data Report is not copyrighted. Readers are free to duplicate and use all or part of the information contained in this publication. Data are not copyrighted and may be used without permission if appropriate citation information is provided.

Pursuant to 42 U.S.C. 1320b-10, this publication may not be reproduced, reprinted, or redistributed for a fee without specific written authorization from HHS.

Suggested Citations:
Full citation: Organ Procurement and Transplantation Network (OPTN) and Scientific Registry of Transplant Recipients (SRTR). OPTN/SRTR 2021 Annual Data Report. U.S. Department of Health and Human Services, Health Resources and Services Administration; 2023. Accessed [insert date]. http://srtr.transplant.hrsa.gov/annual_reports/Default.aspx
Abbreviated citation: OPTN/SRTR 2021 Annual Data Report. HHS/HRSA; 2023. Accessed [insert date]. http://srtr.transplant.hrsa.gov/annual_reports/Default.aspx

Publications based on data in this report or supplied on request must include a citation and the following statement: The data and analyses reported in the OPTN/SRTR 2021 Annual Data Report have been supplied by the United Network for Organ Sharing and Hennepin Healthcare Research Institute under contract with HHS/HRSA. The authors alone are responsible for reporting and interpreting these data; the views expressed herein are those of the authors and not necessarily those of the U.S. government.

This report is available at https://srtr.transplant.hrsa.gov. Individual chapters may be downloaded.