Table 5 Detailed characteristics of included publications (N = 38)

1. Focus

 Vulnerability (27): 38–40, 42, 43, 45–48, 51–55, 57–61, 64, 65, 69–73, 75

 Frailty (9): 41, 44, 49, 56, 62, 66–68, 74

 (both) Frailty and fragility (1): 50

 (both) Vulnerability and frailty (1): 63

2.  Country affiliation of the first author

 Americas (16): Argentina (1): 61; Brazil (1): 64; Canada (2): 44, 53; USA (12): 46, 48, 49, 50, 52, 54, 56, 63, 67, 68, 69, 71

 Europe (18): Austria (1): 57; Germany (1): 42; Ireland (1): 65; Switzerland (2): 41, 73; The Netherlands (5): 39, 40, 58, 59, 72; United Kingdom (8): 43, 47, 51, 60, 62, 66, 70, 74

 Africa (2): 38, 75

 Australia (1): 45

 Indonesia (1): 55

3. Year of publication

 2020–2015 (17): 40–42, 47, 50, 52, 57–59, 62, 64–66, 69, 72, 74, 75

 2014–2010 (6): 38, 39, 46, 55, 61, 68

 2009–2005 (7): 43, 48, 51, 53, 60, 70, 73

 2004–2000 (1): 63

 Before 2000 (7): 44, 45, 49, 54, 56, 67, 71

4. Population under investigation

 Older adults, no specified age and/or gender (22): 39, 40, 42–45, 47, 49–51, 53, 56–59, 66–71, 74, 75

 Older adults, specified age (4): 38 & 41 (+ 65-years-old), 46 (70 and above), 48 (80 and above)

 Older adults in ‘upper middle’ income countries (according to the country list, World Bank) (5): 55, 70, 73 (Indonesia), 60 (Thailand); 61 (Brazil & Argentina)

 Female older adults (2): 54, 63

 Hospitalised older adults (2): 52, 72

 Older adults with dementia (1): 65

 Residents of nursing homes (1): 62

 Cancer, older patients (1): 64

5. Main ethical approach* (21)

 Phenomenology and existentialism (5): 42, 45, 49, 66, 72

 Care Ethics (4): 48, 50, 56, 72

 Feminist Ethics (4): 50, 54, 62, 63

 Principlism (3): 38, 46, 57

 Capability Approach (2): 41, 47

 Public Health Ethics (2): 61, 67

 Virtue Ethics (2): 58, 65

 Analytic political philosophy (1): 75

 Personalistic Ethics (1): 55

Articles that do not explicitly refer to a specific ethical theory or approach (17): 39, 40, 43, 44, 51–53, 59, 60, 64, 68–71, 73, 74