Introduction: Biovigilance risk from cancer or infection in potential deceased organ donors varies and can challenge decision-making. We sought to estimate donation and transplant gains achievable from increasing clinical consistency in potential donor medical suitability decisions.
Methods: Using current Australian and New Zealand clinical guidelines we interrogated a data-linked biovigilance register, to identify and describe potential kidney donors deemed not suitable for transplantation due to a higher than baseline but still guideline-acceptable risk of cancer and/or infection (clinical risk aversion) in NSW, Australia, 2015-2022. We estimated gain in donors per million population (pmp) should these donors have been accepted.
Results: Of 5,211 potential donors deemed not medically suitable and included in our cohort (Figure 1), 674 (13%) were forgone for clinical risk aversion, an average of 84 (1.6%) donors annually.

Of these donors forgone for risk aversion, 317 (49%) had increased risk behaviours for blood-borne viruses but had either no virus, historic Hepatitis B or historic or active Hepatitis C, 539 (20%) had an historic cancer diagnosis of minimum to low transmission risk, and 328 (49%) had a current other treatable infection with no evidence of sepsis or organ damage. Donors forgone for risk aversion were majority male (62%), over 55 years (75%), with one or more comorbidities (85%).

The proportion of potential donors forgone for risk aversion increased to over 40% in 2017, after the introduction of real-time access to centralised cancer records (CCR) (Figure 2). Clinical risk aversion fell again after donor infection and malignancy transmission guidelines were revised in 2019 and 2021. In 2022, 4% of potential donors forgone were due to clinical risk aversion.
Accepting donors deemed not medically suitable and forgone for clinical risk aversion could have increased annual NSW donation rates by up to 4.9 to 9.9 donors pmp, assuming 55% and 100% donor consent rates, respectively. In particular, donors with current Hepatitis C would require the recipient's informed consent and treatment.
Conclusion: Clearer guidelines and organ donation system changes decreased the proportion of donors forgone for clinical risk aversion. However, there remains significant clinical risk aversion for many donors with biovigilance concerns who could have safely donated. Accepting these donors could increase donation rates from 17.5pmp in NSW to 22.4pmp, significantly impacting Australia's rates overall. Challenging risk-averse decisions could provide viable transplant opportunities nationwide.