T YING1,2,A TRAN2, AC WEBSTER2, H PILMORE3, P KELLY2, JS GILL4, S KLARENBACH5, S CHADBAN1,2, RL MORTON2
1Royal Prince Alfred Hospital, Camperdown, Australia, 2University of Sydney, Camperdown, Australia, 3Auckland City Hospital, Auckland, New Zealand, 4University of British Columbia, Vancouver, Canada, 5University of Alberta, Edmonton, Canada
Aim: To calculate the cost-effectiveness of repeated screening of kidney transplant candidates (KTC) for asymptomatic coronary artery disease (CAD) versus no screening (after wait-listing) from a health system perspective, and identify areas of current evidence uncertainty to be addressed in a forthcoming randomised trial.
Background: KTC often wait 2-6 years on the deceased-donor wait-list; cardiovascular fitness must be maintained prior to transplantation. Regular screening by non-invasive methods for CAD is routinely performed at many transplant centres; however the cost-effectiveness of this practice is unclear.
Methods: We developed a Markov model over a lifetime horizon to simulate a cohort of KTCs to undergo annual CAD screening compared with no further screening. We obtained quality-of-life utilities and probabilities of important clinical events including myocardial infarction, transplantation and death using published data. Resource use and costs were obtained from Australian Refined Diagnosis Related Groups, Medicare Benefits Schedule, the Australian Institute of Health and Welfare reports and the literature.
Results: In the base model, no further screening resulted in a cost-saving of $91,025 and additional 2.26 quality-adjusted life-years (QALYs) compared to annual screening. The lifetime costs of an average 40-year old undergoing annual screening was $1,467,078 compared with $1,376,052 for no screening. Annual screening yielded 11.16 QALYs vs 13.42 QALYs in the no-screening arm. Results were most sensitive to the costs of cardiovascular-death and the costs of transplantation in the first and subsequent years.
Conclusion: No further screening for asymptomatic CAD in KTCs is likely to be cost-saving. Detailed data on the real costs of cardiovascular events is required to reduce uncertainty in the results. The Canadian-Australasian Randomised trial of Screening Kidney transplant candidates seeks to answer this question.
Tracey Ying is a nephrologist and a PhD candidate in kidney transplantation at the Kidney Node, Charles Perkins Centre at the University of Sydney