Each health state is associated with a preference value between 0 (death) and 1 (full health). This preference scale between 0 and 1 is cardinal implying that the difference between 0.1 and 0.2 is as large, in terms of preference intensity, as the difference between 0.9 and 1.
5.1 Priority setting at the bedside level
Starting by examining rationing at the bedside level let us assume that there are three patients: Ali, Boris, and Cecilia are all in need of health care, and the cost of treating them is the same.
Ali is at severe impairment (0.2) and can be benefited to no impairment (1) i.e. total increment is 0.8.
Boris is at slight impairment (0.6) and can be benefited to no impairment (1) i.e. total increment is 0.4.
Cecilia is at severe impairment (0.2) and can be benefited to slight impairment (0.6) i.e. total increment is 0.4.
In a choice between whether to treat Ali or Boris, a focus on their HN as well as a focus on their HCN would prescribe that Ali should be prioritized. However, understanding needs in terms of different distributive theories of justice give preference to Ali for different reasons: (i) When employing an egalitarian distribution among needs the reason for choosing Ali is the comparative factor, i.e. that Ali has a greater HN in relation to Boris; (ii) when employing a prioritarian distribution among needs the reason for choosing Ali is that it matters more to benefit him as he has a greater HN (in absolute rather than relative terms); (iii) when employing a sufficientarian distribution among needs the reason for choosing Ali is that Ali’s HN is great to the extent that he is located below the threshold (given that the threshold level is placed at, for example, preference level of 0.4). Note, however, that if there was a fourth person David, located at 0.5 and who could be benefitted to 1, sufficiency principles would be indifferent between Boris and David even though David is worse off than Boris.
This course of action also follows from CEP and does so because it provides the greatest net sum of utility; in this way CEP gives indirect priority to the worse off. Note that while any need principle does so because Ali is worse off this is a mere consequence of CEP. Consequently, while there is no necessary conflict between principles of need and CEP in terms of which allocation decision, there is an important difference between CEP and principles of need regarding the underlying reason for why Ali should get priority over Boris.
In a choice between whether to treat Boris or Cecilia any weight given to the HN imply that Cecilia ought to be treated instead of Boris since Cecilia’s HN is greater. Again, an egalitarian distribution among needs would have this implication based on the comparative factor, a prioritarian distribution because Cecilia has a greater HN in absolute terms while a sufficientarian distribution among needs opts for Cecilia because her HN is great to the extent that she is located below the threshold while Boris is not. Priority setting according to CEP, however, would be indifferent since Cecilia and Boris’ HCNs are equally great (both alternatives generate the same increase in utility).
It may be argued that CEP indirectly gives increasing weight to people the greater their HN are and hence has already accounted for the importance of being worse off. If we assume that people’s preference value is capturing utility, CEP accounts for being worse off as the thesis of diminishing marginal utility adjusts for this. Thus, it would necessitate a larger health increase in absolute terms to move from 0.2 to 0.6 than from 0.6 to 1. This implies that the extent to which CEP accounts for the importance one may ascribe to the extent to which one has a great HN being worse off partly depends on the extent to which the thesis of diminishing marginal utility for health is true, and to some extent on the adequacy of the methodology one employs to assess utility (see e.g. [
54] for further discussion on the validity of utility measurements). In contrast, any principle of need involves a normative claim that there is something of special moral importance about having large HN (being worse off), regardless of whether, and if so to what extent, the preference value for different health states accounts for the diminishing value of health.
Along these lines it may be argued that decision-makers, who take both some principle of need and CEP into account, are unknowingly including the same moral value twice when setting priorities, i.e. they are double counting the moral value of being worse off. But even though CEP may account for the size of some people’s HNs, the normative implication of principles of need, again, in any version is that there should be additional weight put on health improvements accruing to people the greater their HN is. Hence, the moral value of being worse off is not double counted. Rather principles of need ascribe extra weight in addition to whatever concern for the worse off accounted for by diminishing marginal utility.
In practice this line of reasoning could appear when decision-makers apply some threshold level for what society considers to be a reasonable cost per QALY, and fund interventions with a cost per QALY below the threshold but not above. Traditionally when setting priorities according to CEP a key normative assumption is that a QALY is of equal value irrespective of to whom it accrues [
57]. That is, it is equally valuable independent of the size of the HN carried by the patient (or patient group). This implies that society applies some threshold level for a reasonable cost per QALY. Interventions below the threshold get funding while interventions above do not. Setting priorities according to principles of need, however, does not involve such a normative assumption. Instead, an intervention for a patient with a higher cost per QALY could be justified if it relates to a patient who has a greater HN. For example, this is illustrated by the approach outlined in the final report laid out by the Norwegian Committee on Priority Setting in the Health Sector in 2014 [
58,
59].
Finally, in a choice between whether to treat Ali or Cecilia, the recommendation given by CEP is to prioritize Ali rather than Cecilia since this maximizes utility gained. One may interpret principles of need as being indifferent with regard to who should get an intervention since both patients’ HNs are equally great. For example, that is what the sickest first principle would imply as this principle exclusively focuses on the greatness of the HN. However, it could be argued that the more a patient is benefited (i.e. the greater his or her HCN is) the stronger his or her need-based claim is [
16]. Hence, also in this case principles of needs and CEP may imply the same course of action, and in this case for more similar reasons.
5.2 Priority setting at the policy level
To explore aspects relating to how the different approaches relate to the issue of aggregation of health benefits across individuals, let us consider the same case at the policy level. This entails making decisions about treatments for specific patient groups.
Patient group A contains a small number of patients which are (in all relevant aspects) like Cecilia (at 0.2 and may be benefited to 0.6).
Patient group B contains a somewhat larger number of patients which are (in all relevant aspects) like Boris patients (at 0.6 and may be benefited to 1).
As in the bedside case, we assume that the total cost of treating the two groups is the same. Hence, there is a lower cost per health unit to get patients from group B from 0.6 to 1 than to get patients from group A from 0.2 to 0.6. The application of CEP as the guiding principle here would imply that group B rather than A should get priority, since this allocation provides the greatest sum of aggregated utility.
How does principles of need relate to such a case on the macro level and aggregation? Whereas the conventional need principles could easily be applied to the bedside case their implications at the policy level is less clear. In regulatory guidelines it is sometimes suggested that principles of need are incompatible with aggregation [
3]. But this seems like a rather implausible view in practice given that; if decision makers are to take costs into account at the policy level (which seems quite uncontroversial) this implies an opportunity cost, i.e. to consider how a given resource
could have been used elsewhere. It seems difficult to account for the opportunity cost if all kinds of aggregation are prohibited. A more plausible principle of need should therefore arguably allow for some restricted form of aggregation. To characterize a method of aggregation compatible with ideas about need-based priority setting is an important task with regard to the plausibility of principles of need [
60].