BackgroundVulnerability is a key concept in traditional and contemporary bioethics. In the philosophical literature, vulnerability is understood not only to be an ontological condition of humanity, but also to be a consequence of contingent factors. Within bioethics debates, vulnerable populations are defined in relation to compromised capacity to consent, increased susceptibility to harm, and/or exploitation. Although vulnerability has historically been associated with older adults, to date, no comprehensive or systematic work exists on the meaning of their vulnerability. To fill this (...) gap, we analysed the literature on aged care for the meaning, foundations, and uses of vulnerability as an ethical concept.MethodsUsing PRISMA guidelines, we conducted a systematic review of argument-based ethics literature in four major databases: PubMed, Embase®, Web of Science™, and Philosopher’s Index. These covered biomedical, philosophy, bioethical, and anthropological literature. Titles, abstracts, and full texts of identified papers were screened for relevance. The snowball technique and citation tracking were used to identify relevant publications. Data analysis and synthesis followed the preparatory steps of the coding process detailed in the QUAGOL methodology.ResultsThirty-eight publications met our criteria and were included. Publication dates ranged from 1984 to 2020, with 17 publications appearing between 2015 and 2020. Publications originated from all five major continents, as indicated by the affiliation of the first author. Our analyses revealed that the concept of vulnerability could be distinguished in terms of basic human and situational vulnerability. Six dimensions of older adults’ vulnerability were identified: physical; psychological; relational/interpersonal; moral; sociocultural, political, and economic; and existential/spiritual. This analysis suggested three ways to relate to older adults’ vulnerability: understanding older adults’ vulnerability, taking care of vulnerable older adults, and intervening through socio-political-economic measures.ConclusionsThe way in which vulnerability was conceptualised in the included publications overlaps with distinctions used within contemporary bioethics literature. Dimensions of aged care vulnerability map onto defining features of humans, giving weight to the claim that vulnerability represents an inherent characteristic of humans. Vulnerability is mostly a value-laden concept, endowed with positive and negative connotations. Most publications focused on and promoted aged care, strengthening the idea that care is a defining practice of being human. (shrink)