Ambiguous Invitations: non-maleficence, uncertainty and public health policy

Abstract

Consider two paradigm examples of public health programmes: routine screening for early stage cancer, and vaccination against infectious diseases. Both interventions are often controversial. Typically, these controversies centre around questions of evidence: many within the medical community worry that the evidence basis for the effectiveness of screening is weak (Welch and Black, 2010; McCartney, 2012). Similarly, vaccination sceptics raise concerns about whether we can be certain that vaccinations are safe (Irzik and Kurtulmus, 2019). A second shared feature is that these interventions are typically initiated by invitations; through letters inviting you to attend a screening appointment, or text messages inviting you to vaccinate. You might think that this second feature is largely irrelevant to the first; whether there is sufficient evidence to introduce screening or vaccination programmes depends on much the same considerations as whether there is sufficient evidence to introduce other public health interventions such as clean air regulations. This paper argues for the opposite: when a medical intervention is initiated by an invitation, such as in screening programmes, we should require very strong evidence before implementing that intervention. This principle is not costless, because, as I explain below, it implies a conservatism which, over time, leads us away from doing as much good as possible. This deviation from the demands of Beneficence is justified, I suggest, because when we engage in the speech act of inviting, we trigger norms of non-maleficence, which, in turn, require a distinctive attitude towards acting under uncertainty.