Determining priority for liver transplantation

A comparison of the implications of the application of the principles of equity and efficiency as two desirable but competing attributes of the organ allocation system. Efficiency is defined in economic terms as the standard cost per QALY model and equity considerations are included in a model based on public preferences generated from a discrete choice experiment in determining priority for donor liver graft allocation.

A survey of the general public (n = 303) using a discrete choice experiment was undertaken. The results enabled estimation of the relative weights attached to several key factors which might be used to prioritise patients on the waiting list for liver transplantation. These weights were then used to develop a patient-specific index (PSI) for all patients diagnosed with one of three main chronic liver diseases who had received a liver transplant during an 18-month period at all Department of Health designated liver transplant centres in England and Wales (n = 207). The cost per QALY model comprised net total costs from assessment to 27 months following assessment as the numerator of the ratio. Net survival over the same time period, adjusted for HR-QOL using population values for the EQ-5D descriptive system, formed the denominator.

Priority for liver transplantation differed markedly according to whether patients were ranked according to efficiency (net cost per QALY) or equity considerations (PSI) and the differences in ranks were found to be statistically significant (Wilcoxon signed rank test p < 0.001).

This study emphasises that the priorities of the general public may not accord with those arising from a pure efficiency objective and quantifies the extent of the efficiency loss in terms of lost QALYs and increased net programme costs associated with the incorporation of equity concerns as reflected in public preferences for the allocation of donor livers for transplantation.