There are two important arguments against allowing out-of-pocket payment for expensive anti-cancer treatments. Because these arguments may be less self-evident, they merit more extensive analysis, in order to understand the dilemma of allowing out-of-pocket payments within universal healthcare systems.

A first reason not to allow patients to pay for treatments out of pocket is to protect them against potential harms. This is in line with the principle of non-maleficence (Beauchamp and Childress 1979), which refers to the Latin adage “primum non nocere,” which means “above all, do no harm” (Smith 2005). This principle was part of the classical Hippocratic Oath, as reflected in the phrase: “I will keep them [the ill] from harm and injustice’’ (Askitopoulou and Vgontzas 2018).

In the context of expensive anti-cancer treatments, various types of harm to the individual patient can be identified. Firstly, there is a risk of potentially harmful side effects of the treatment. As said, however, this article focuses on anti-cancer treatments which are approved for marketing by the relevant drug regulatory authorities, and thus, are proven safe and (at least minimally) effective, and the potential for harmful side effects is no different from other (reimbursed) medical treatments. Thus, any potential for harm due to side effects does not serve as a valid counterargument against out-of-pocket payments. Secondly, out-of-pocket payments could have serious financial consequences for patients. This type of harm—referred to as “financial toxicity,”—by contrast, does occur uniquely in a context in which patients fund medical treatments themselves, and may need to make sacrifices to do so. Some patients may put themselves in debt or sell their house to be able to pay for treatments. A questionnaire-based study in the United Kingdom, for instance, showed that among patients and members of the general public, 22 per cent would remortgage their house to pay for medical treatments (Jenkins et al. 2011). Financial toxicity is associated with lower quality of life, stress, and anxiety (Arastu et al. 2020). Some patients are more at risk for financial toxicity than others. An Israeli study showed that the risk of financial burden of out-of-pocket spending was lower for patients with an above-average income or better education (Tur-Sinai et al. 2022). Not all patients may succeed in amassing the funds, leading to “subjective financial distress” (Carrera, Kantarjian, and Blinder 2018). Although we could not find any literature on whether and to what extent patients or their family members would suffer from financial toxicity if out-of-pocket payments were allowed in universal healthcare systems, we believe that, given the enormous costs of many new anti-cancer treatments, there is a significant probability that they might. Disallowing out-of-pocket payment would help prevent individual patients against financial burdens and hardship.

Also, allowing out-of-pocket payments in a universal healthcare system might possibly be harmful to other patients. If it is, the harm principle may come into play. For other patients, healthcare professionals, and possibly citizens in egalitarian healthcare systems, being confronted with unequal opportunities to access healthcare—especially when this occurs within the same hospital or region—may have adverse impact on psychological well-being (Weale and Clark 2010). In the literature, negative psychological effects have been described of allowing top-up fees or private payments for cancer care in countries with two-tier healthcare systems such as New Zealand and the United Kingdom (Fenton 2011; Sikora and James 2009; Bloor 2008; Gubb 2008; Richards M. 2008). If allowing out-of-pocket payments were to harm others, psychologically, it would run counter to the principle of non-maleficence.

Other others-affecting types of harm occur on a macro-economic level. The first is displacement of healthcare. This might occur, for instance, if for the administration of treatments and for monitoring and follow up of any adverse events, patients need to make use of public hospital beds, equipment, and staff. While patients who pay out of pocket could also be charged for the ancillary costs associated with these services, in the context of increasing absolute scarcity in healthcare, they might usurp facilities and staff that, as a result, would no longer be available for other patients who rely on the publicly funded healthcare system. As this might not only harm other patients but also lead to unjust distribution of resources, displacement of care could both be seen as a problem of harm and a problem of justice. A recent study in the Netherlands suggests that displacement of care based on the introduction of new expensive technologies had not yet occurred (Wammes et al. 2020). However, little is known about whether out-of-pocket payments or top-up fees would lead to displacement of care in universal healthcare systems. If out-of-pocket payments were to lead to displacement of care, allowing them would be undesirable, as it would hinder the accessibility of care for other patients, which would be harmful to them.

The second is the potential for allowing out-of-pocket payments to undermine the bargaining power of governments. If pharmaceutical companies can tap into private markets, they may not be incentivized to lower their prices or fulfil the cost-effectiveness requirements of publicly funded systems, and may not be included in the basic package of healthcare that is accessible for all patients. If out-of-pocket payments were thus to lead to higher drug prices, governments would need to restrict inclusion of newly approved treatments in the basic package even further, to increase the premiums of mandatory health insurance or to cut down on healthcare generally, potentially lowering the quality of basic healthcare, all of which would negatively affect all citizens. However, allowing out-of-pocket payments might also have the opposite effect; if it were to contribute to the affordability of the healthcare system, as some treatments would then not have to be reimbursed collectively, and if it were to leave more funds available for other, more cost-effective treatments, this could potentially benefit all citizens, including the worst-off. To our knowledge, none of these effects—specific to (dis)allowing out-of-pocket payments—have been reported in the literature. Consequently, it is currently not clear whether allowing out-of-pocket payment has adverse effects on the scope or quality of healthcare provided within publicly funded healthcare systems.

Health policies should not be harmful to individual patients nor lead to harm to others. In order to determine whether allowing out-of-pocket payments in publicly funded healthcare systems is harmful—through financial toxicity or psychological burdens, or by displacing care or depleting the healthcare system—further empirical research is needed.

A second main argument against allowing patients to pay for treatments out of pocket, is that it could potentially lead to unequal access to medical treatments among patients. Universal healthcare systems are based on the notion that every citizen should have equal access to healthcare based on medical need only, and regardless of their financial means, social status or other contingent factors. This commitment to ensure equal access to healthcare for every citizen follows from the principle of justice (Beauchamp and Childress 1979), which implies that health resources should be fairly distributed. However, there is no consensus on what fair distribution is. According to Norman Daniels, who has translated Rawls’s justice theory to the medical domain, healthcare should be distributed in such a way, that it promotes equal opportunities to participate in society (Daniels 2001). In a context of scarcity, Daniels’s theory implies that patients who need care the most in order to enjoy a normal range of opportunities, should be prioritized over others. Also, it implies that government spending on healthcare should be curtailed, so that other preconditions for having opportunities in life, such as education and safety, can be met. It follows that it is just for publicly funded healthcare systems not to reimburse treatments that are insufficiently cost-effective. However, Daniels’s theory does not explicitly address the question whether or not it is just for publicly funded healthcare systems to allow patients to pay out of pocket for non-reimbursed treatments.

There is only one set of theories of justice that does, namely: egalitarian theories of justice. Egalitarian theories of justice consider equality desirable and inequality undesirable in and of itself (Parfit 1997). These theories would point out that by allowing patients to pay for treatments themselves, a form of inequality is introduced: more affluent patients will have the opportunity to obtain access to non-reimbursed treatments, while less affluent patients will not. And if patients were to start crowdfunding campaigns to help shoulder the costs of non-reimbursed treatments, this would introduce further inequities within society (Snyder 2016). As long as the treatment cannot be made available to all patients, egalitarian theories go, it will be preferable to keep more affluent patients from obtaining access using private funds, even if this results in the treatment not being available at all. This phenomenon is known as “levelling down” (Eyal 2013), which means, in short, that if not everyone can get X, then no one should get X. Critics have argued against the fairness of this phenomenon, making the so-called levelling down objection (Parfit 1997). The objection entails that, if the worst-off (patients unable to pay out-of-pocket) are not becoming better off, but the well-being of the best-off (patients able to pay out-of-pocket) is reduced to the level of the worst-off, we have gained nothing good (Parfit 1997). For instance in the case of Trodelvy, it would be considered unjust to prevent patients from getting access to the drug and thereby deprive them of the chance of (on average) five months of life prolongation, just because not all patients can get access.

According to Rawls, there is one condition under which social inequalities can be morally acceptable, namely: this is when inequalities will benefit the citizens who have the least opportunities—those who are worst off. This he calls the “difference principle” (Rawls 1971). It follows from the difference principle that in order to determine whether or not allowing out-of-pocket payment for non-reimbursed treatment is just, it is important to assess whether it will or will not ultimately benefit the worst-off. Further empirical research will be needed to ascertain whether allowing out-of-pocket payments will lead to displacement of healthcare or depletion of the healthcare system or, by contrast, whether it will help relieve some of the financial pressures within the healthcare system and thus contribute to its sustainability, and thus will come to benefit the worst-off.

While according to egalitarian theories of justice, a policy of allowing out-of-pocket payments may not be morally desirable as it introduces inequalities in access to medical treatments, the theory of justice developed by Rawls and Daniels seems to leave room for allowing out-of-pocket payments as long as it may ultimately come to benefit the worst-off.

Solidarity is another fundamental value underlying publicly funded healthcare systems. In the Netherlands, the National Health Care Institute, which advises the Ministry of Health, Welfare and Sports about which treatments to include in the basic health insurance package, describes its objectives on their website as follows:

“Every person residing or working in the Netherlands is entitled to good care services from the standard health insurance package. Our healthcare system is based on the principle of solidarity. Rich and poor, young and old, healthy and sick: everyone in the Netherlands has access to the same care.” (Zorginstituut Nederland 2021)

While the interpretation of solidarity may differ across European healthcare systems, solidarity is often seen as an important value (Saltman 2015).

The concept of solidarity is used in different ways. It can be seen as the promotion of equality—therefore sharing some similarities with egalitarian justice—but also as assisting patients in need, upholding a solidarity-based healthcare system or willingness to contribute (van Till et. al. 2023). Often, solidarity is used to refer either to a feeling, of “togetherness” or “unity,” or to a predisposition, a willingness to help people in need. Barbara Prainsack and Alena Buyx, who describe solidarity as a predisposition, define solidarity in the context of bioethics as follows: “solidarity signifies shared practices reflecting a collective commitment to carry ‘costs’ (financial, social, emotional or otherwise) to assist others” (Prainsack and Buyx 2012, 346). They distinguish three “tiers” on which solidarity becomes manifest: on the interpersonal level, in group practices, and on a societal level (Prainsack and Buyx 2012). All three of these tiers can be applied to out-of-pocket payments. Solidarity on an interpersonal level takes place between individuals, when people demonstrate a willingness to carry costs for others based on certain similarities. For instance, solidarity can be seen when people are willing to contribute financially to the non-reimbursed medical treatment of someone else through crowdfunding. On the second tier, solidarity becomes manifest within groups as a form of social behaviour based on a feeling of “being in the same boat.” Patients may (need to) choose to refrain from out-of-pocket payments for non-reimbursed medical treatments when they know that others, who are less affluent, will not be able to buy those same treatments. The third tier of solidarity takes place on a societal level and is expressed in contractual and legal arrangements. This is also seen in the Dutch healthcare system, in which everyone must contribute to the healthcare system by paying taxes and, in return, everyone has equal access to healthcare. On this tier, solidarity can thus be imposed by governments (Prainsack and Buyx 2012). Prainsack and Buyx also state that the third tier leans on the first two tiers. To be able to sustain a universal healthcare system based on solidarity, there has to be support for this within society and a feeling of togetherness amongst individuals. Thus, to be able to maintain such a healthcare system, the “willingness to carry costs” among citizens has to be safeguarded. This willingness to carry cost for the sake of others, within societies, will likely not be infinite. If citizens are obliged to make rising and very high (monthly) financial contributions to the universal healthcare system, the predisposition of solidarity (on tiers 1 and 2) could crumble. This is another reason (apart from justice) why governments should critically assess the cost-effectiveness of newly approved medical treatments and limit the basic healthcare package, to prevent mandated financial contributions from citizens from skyrocketing. Depending on the notion of solidarity used, solidarity may serve as an argument either for or against allowing out-of-pocket payments: on the one hand, helping or allowing patients to access non-reimbursed treatments can be seen as an expression of (tier 1) solidarity, namely, as a willingness to carry costs to help those in need. On the other hand, if solidarity is taken to mean “being in the same boat” (on the second tier), it may imply that affluent patients should refrain from pursuing access if other, less affluent patients, are not in the position to obtain the same benefits. Thus, out-of-pocket payments may not be conducive to sustaining a solidaristic healthcare system.