Abstract
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Evidence based medicine supports net benefit maximising therapies and strategies in processes of health
technology assessment (HTA) for reimbursement and subsidy decisions internationally. However,
translation of evidence based medicine to practice is impeded by efficiency measures such as cost per
case-mix adjusted separation in hospitals, which ignore health effects of care.
In this paper we identify a correspondence method that allows quality variables under control of
providers to be incorporated in efficiency measures consistent with maximising net benefit. Including
effects framed from a disutility bearing (utility reducing) perspective (e.g. mortality, morbidity or
reduction in life years) as inputs and minimising quality inclusive costs on the cost-disutility plane is
shown to enable efficiency measures consistent with maximising net benefit under a one to one
correspondence. The method combines advantages of radial properties with an appropriate objective of
maximising net benefit to overcome problems of inappropriate objectives implicit with alternative
methods, whether specifying quality variables with utility bearing output (e.g. survival, reduction in
morbidity or life years), hyperbolic or exogenous variables. This correspondence approach is illustrated in
undertaking efficiency comparison at a clinical activity level for 45 Australian hospitals allowing for their
costs and mortality rates per admission. Explicit coverage and comparability conditions of the underlying
correspondence method are also shown to provide a robust framework for preventing cost-shifting and
cream-skimming incentives, with appropriate qualification of analysis and support for data linkage and
risk adjustment where these conditions are not satisfied.
Comparison on the cost-disutility plane has previously been shown to have distinct advantages in
comparing multiple strategies in HTA, which this paper naturally extends to a robust method and
framework for comparing efficiency of health care providers in practice. Consequently, the proposed
approach provides a missing link between HTA and practice, to allow active incentives for evidence based
net benefit maximisation in practice.