Physical Domains, Access to Kidney Transplantation, and Waitlist Mortality

Area of Science:

• Nephrology
• Transplantation
• Geriatrics
• Public Health

Background:

• Frail kidney transplant (KT) candidates often exhibit low physical activity and function, diminishing their chances of being listed and increasing mortality risk.
• These physical impairments can worsen perceived physical burden, creating a cycle that negatively impacts outcomes.
• Understanding individual associations between physical activity, function, and burden with adverse events is crucial for improving pre-KT risk stratification.

Purpose of the Study:

• To investigate the associations of physical activity, physical function, and physical burden with KT listing and waitlist mortality.
• To identify which physical domain is the strongest predictor of adverse outcomes in KT candidates.

Main Methods:

• A prospective cohort study included 2708 KT candidates (age ≥ 18) from two centers (2014-2024).
• Physical activity (Minnesota Leisure Time Physical Activity Questionnaire), physical function (gait speed), and physical burden (Kidney Disease Quality of Life Short Form) were assessed.
• Cox proportional hazards and competing risks models were used to quantify associations with listing and waitlist mortality.

Main Results:

• Among 2708 candidates, 40% had low physical activity, 16% low physical function, and 54% high physical burden.
• Impairments in all three domains were linked to lower likelihood of KT listing (aHRs ranging from 0.54 to 0.86) and higher waitlist mortality risk (aSHRs ranging from 1.40 to 1.83).
• Physical burden demonstrated the strongest predictive ability for mortality (Harrell's C-statistic = 0.6899).

Conclusions:

• Physical activity, function, and burden impairments are all associated with KT listing and waitlist mortality.
• Physical burden is the most significant predictor of waitlist mortality among these physical domains.
• KT centers should consider incorporating physical burden assessment as a simple, cost-effective tool for identifying high-risk candidates for prehabilitation.