Screening and non-maleficence

Even where screening programmes are effective, it remains the case that a net aggregate benefit is compatible with harm to many specific individuals. It is worth noting here that my concern is with uncompensated harms. By this, I mean harms that are incurred by individuals who gain no benefit from screening. In other words, while an individual who is diagnosed with cancer through their participation in a screening programme may undergo painful cancer treatment, this harm is morally outweighed if the early detection of their cancer prolonged their life. For other individuals, however, screening leads to overdiagnosis: the detection of abnormalities which would never have progressed to cause harm. This results in many patients receiving treatment that is medically unnecessary, such as cervical excision to treat precancerous cells which might have regressed spontaneously. Overtreatment has its own consequences: women undergoing cervical excision, for example, are more likely to experience preterm labour.4

That screening causes harm appears to violate non-maleficence, one of the core principles of medical ethics as outlined by Beauchamp and Childress.5 Non-maleficence stems from the axiom primum non nocere—‘first, do no harm’. Yet it is evident that medical professionals often do harm their patients in order to achieve some greater benefit: a surgeon may, for example, amputate a patient’s gangrenous leg in order to save their life. How can we distinguish harms which are ‘acceptable’ from those that are ‘unacceptable’? I would argue that we can morally justify the harm of amputating a patient’s gangrenous leg on the grounds that it is medically necessary to save their life, but that we cannot justify amputating both of their legs if amputation of only one would bring about the same benefit. In other words, harm is medically necessary—and thus morally acceptable—if it is the least harmful means of generating a greater benefit for a given patient. I therefore define non-maleficence as a prima facie obligation not to cause harm which is medically unnecessary. The distinction between medically necessary and unnecessary harm is useful in that it makes clear why we might deem it unacceptable for a patient’s healthy leg to be amputated in order to save another patient’s life. Amputating a patient's leg to save their own life carries the same net benefit as amputating a patient's leg to save another patient's life, but the latter case involves medically unnecessary harm.

Imagine, though, that in order to save a patient’s life we must infect another patient with a cold. Perhaps, the relative balance of harm and benefit in this case might lead us to believe that the infliction of a medically unnecessary cold is morally acceptable. However, given that harms of screening include unnecessary mastectomies,6 I would suggest that the harm inherent in screening is more akin to leg amputation than to a cold. As a result, we cannot easily override non-maleficence in screening whenever there is an overall benefit, since it is tricky to mandate serious and medically unnecessary harm on some individuals even where it brings about a net population benefit. How, then, might we resolve the issue of non-maleficence in screening? One possible answer is to suggest that screening-related harm can only be justified where expected benefit to a particular individual outweighs expected harm to that same individual. This, however, is an impossible standard: for any particular individual screened, we cannot know, at the outset, whether the benefit to them outweighs the harm. More than this, I would argue that we cannot know this even after screening has taken place, since to assess the balance of benefit and harm requires counterfactual knowledge of what would have happened had we not intervened. This is difficult, if not impossible, to obtain.

Resolving the balance of population-level beneficence and individual-level non-maleficence is, evidently, a tricky endeavour. Might there be an easier way to justify harm in screening? Although screening necessarily causes medically unnecessary harm, any given individual participating in screening could, in principle, benefit: screening-related harm results from risks imposed on an individual in order to benefit either that individual or others. In this way, screening can be viewed as a sort of lottery. It is much more likely that a lottery participant will be harmed by losing the money spent on the lottery ticket than that they will benefit by winning the jackpot. The potential benefit, however, is great, which may make the harm of wasting money seem insignificant in comparison. In buying a lottery ticket, a participant therefore takes on a risk which will result in benefit either to themselves or to others. If we are to accept that both lotteries and screening confer great benefit on at least some individuals, it might be argued that a rational agent may wish to accept the invitation to screening—despite the harms it might entail—on the basis that they stand to potentially benefit. If an individual wishes to accept the invitation, can their consent to the offer make morally irrelevant any harm they might suffer?

The problem of consent in preventive medicine

Let us first consider the moral status of consent as it applies to therapeutic medicine. Consent does moral work by ‘justifying action that would otherwise violate important norms, standards or expectations’.7 Where a patient gives their consent to the amputation of their gangrenous leg in order to save their life, they render morally permissible an action which would usually violate important norms. In order for their consent to be valid, it must be both informed and autonomous; in other words, they must have sufficient information about the consequences of the action to which they give their consent, and be free of pressuring influences.1 These principles of consent—well-established in therapeutic medical contexts—have historically been applied unproblematically to screening. However, several authors have hinted at the idea that there is an ethical distinction between ‘everyday’ medical practice and preventive interventions such as screening.8 9 Those who make this argument suggest that preventive medicine is ethically different to therapeutic medicine, although few have outlined exactly why. In this section, I aim to demonstrate that there is a pragmatic difference between the patient-initiated requests of therapeutic medicine and the doctor-initiated invitations of preventive medicine. This changes the ethical responsibilities which must be borne by the doctor, and the terms by which consent can be expected to do moral work.

In therapeutic medicine, the patient presents to a doctor with a concern: most often, a symptom or set of symptoms. A patient makes a request for this concern to be addressed by the doctor, thereby entering into a transaction in which the ‘special social and cognitive authority’ of the doctor is acknowledged.10 In screening, the transaction is different. Here, a doctor approaches an individual who has not sought out a medical encounter, and invites her to participate in screening. If we make a distinction between the contexts of patient-initiated requests and doctor-initiated invitations, how might this lead us to conclude that consent to the latter cannot meet the transactional demands of consent? Approaching healthy individuals with the invitation to participate in a medical intervention disrupts the normal framework of the therapeutic doctor–patient encounter in which a patient makes a request of the doctor. If, as Rebecca Kukla argues, the ‘rituals of the clinic’ are ‘essential to giving the transaction [of consent] the pragmatic form it has’,10 then we cannot expect the same formulation of consent to automatically apply in the case of preventive medicine. In the rest of this section, I will argue that invitations to screening present a problem on two grounds: first, that the pragmatics of making a medical invitation are such that a patient is liable to be misinformed; and second, that to make a medical invitation at all may constitute an inducement to accept.

Improving consent

Are we to conclude that patients are irreconcilably misinformed about screening? Are invitations to screening always inherently coercive? Not necessarily. As I have outlined, the pragmatic form of an invitation to screening may mean that patients are pressured into accepting, or misinformed about its implications. Perhaps, though, we could see the pragmatic form of a screening invitation as a kind of framing effect, leading patients to perceive screening differently on account of how the invitation is made and who it is made by. How might we tackle the issue if we were to view it as a framing effect? Chwang3 argues that a patient’s consent may be invalidated where framing effects are present, but that this consent can be revalidated by ‘debiasing’: alerting patients to the framing effects to which they are subject. Thus, rather than simply presenting patients with information (eg, that an intervention has 10% mortality and/or 90% survival), we can instead present metainformation, which highlights framing effects: for example, by explaining to patients that they liable to make a different decision about accepting or rejecting the intervention depending on whether they are told that it has 10% mortality or 90% survival. We can also apply a similar information/metainformation distinction to my earlier example of therapeutic misconception. Research participants are given information: for example, ‘the aim of this research study is to confirm that Drug X is effective in treating cancer’. Despite this, participants still appear to believe that trials are conducted for their own benefit. Perhaps, though, therapeutic misconception could be addressed by providing metainformation: for example, ‘research participants may be given the impression that the research trial is intended to treat their illness, even though this is not its main aim’.

The provision of metainformation is, in my view, the most compelling means to address the issues I have raised in this paper about the pragmatics of medical invitations. What might the provision of metainformation about screening look like? Screening information literature could make clearer the fact that many patients (reasonably) believe that an invitation to screening is made with their best interests in mind, even though it is inevitable that some individuals will be harmed by screening. Similarly, invitations to screening could stress not only that accepting the invitation is a patient’s choice, but also explain that patients may well feel pressured to take up invitations made by their doctor. Such measures would go some way to debiasing patients, since they highlight to patients that their consent to screening is shaped by the fact that they are invited to participate by doctors. If, through debiasing, we are able to eliminate the framing effect brought about by the pragmatic form of a medical invitation, this would negate my concern that such invitations may pressure or misinform patients. In turn, this would allow patients’ consent to screening invitations to do moral work in justifying the harm which patients may incur if they undergo screening.