SRTR Liver Donor Risk Assessment (Feng et al. 2006)
Donor Factors
years
cm
hours
Total cold ischemia time
DRI Calculator
Assess liver donor risk based on donor and organ characteristics.
Guidelines & Evidence
Verified
Last Review: 2026-07-17
When to Use
When to Use
To quantify the relative risk of graft failure for a deceased liver donor
To guide organ acceptance decisions at the time of donor offer
To stratify donor quality for recipient matching and counselling
To benchmark centre-level donor acceptance practices
To support research on donor risk factors and outcomes
Interpretation
The DRI is calculated relative to the "average" deceased donor in the United States. A DRI of 1.0 represents the reference donor. A DRI of 2.0 indicates approximately twice the risk of graft failure compared to the reference. DRI values typically range from approximately 0.7 to > 3.0.
How it Works
DRI Components (Feng et al. 2006)
01
Donor Age: The dominant factor. Risk increases substantially after age 40 and accelerates after 60.
02
Cause of Death: CVA/stroke is associated with higher risk than head trauma or anoxia.
03
DCD (Donation after Circulatory Death): DCD donors carry approximately 50% higher risk of graft failure.
04
Split/Partial Graft: Reduced graft volume increases technical complication risk.
05
Height: Smaller donors (height < 150 cm) are at higher risk, possibly due to reduced functional hepatocyte mass.
06
Sharing Region: Regional and national sharing increase cold ischaemia time and risk.
07
Cold Ischaemia Time: CIT is a continuous risk factor. Each hour beyond 6 hours increases risk by approximately 3%.
Formula
DRI = exp(Σ β_i × X_i)
Where β_i are regression coefficients from the Cox model
Factors multiplied as: age_RR × COD_RR × DCD_RR × split_RR × height_RR × region_RR × CIT_RR
Result is a ratio — 1.0 = average donor risk
Clinical Pearls
Using DRI in Clinical Practice
The DRI is most useful as a comparative tool when deciding between multiple simultaneous organ offers. A DRI of 1.2 vs. 1.8 provides a quantitatively informed basis for the clinical judgment that one donor carries substantially more risk. However, DRI should not be used as a hard cutoff for acceptance. A high-DRI organ may provide significant survival benefit for a high-MELD candidate facing imminent waitlist mortality.
Key Limitations
DRI is derived from US data (1998-2002) — calibration may differ in contemporary practice and other countries
DRI does not capture steatosis severity, donor liver function tests, or biopsy findings
Recipient factors (MELD, age, comorbidity) interact strongly with DRI — the same donor has different risk in different recipients
Centre experience with high-DRI donors varies — individual centre outcomes may deviate from the model
En bloc and paediatric donors have separate risk considerations not fully captured by DRI
Next Steps
Guiding Acceptance
01
DRI < 1.0: Below-average risk. Standard acceptance for most candidates.
02
DRI 1.0-1.5: Average to slightly elevated risk. Appropriate for most candidates.
03
DRI 1.5-2.0: Moderate-high risk. Consider recipient MELD, age, and alternative strategies.
04
DRI > 2.0: High risk (sometimes called "marginal"). May be appropriate for candidates with high waitlist mortality.
The Evidence
Original Derivation
Characteristics associated with liver graft failure: the concept of a donor risk index.
Feng S et al. • Am J Transplant.. 2006;6(4):783–790. n = 20,023 liver transplant recipients (1998-2002). C-statistic 0.65 for graft survival.
View SourceOrigins & History
Background
The DRI was developed by Dr. Sandy Feng and colleagues at the University of California, San Francisco, using data from the SRTR. The work paralleled the development of the KDRI for kidneys and represented a shift toward evidence-based, continuous donor risk assessment in liver transplantation, moving away from binary "acceptable" vs. "marginal" classifications.
Last Comprehensive Review: 2026-07-17