Answer to "I cannot find entrustable and entrustability in the dictionary. How should these words be used?"
This is a very good question. The adjective 'entrustable' and the noun 'entrustability' were first used in 2005 (ten Cate, 2005). They are neologisms, new words that did not exist before.
Entrustable pertains to a property of an activity; it means that the activity can be entrusted to someone to execute. Entrustable professional activities (EPAs) are the units of professional practice that have this property. Entrustability is simply the noun of this property.
A good next question is: do we need these words, in other words, can we think of activities that are not entrustable? Some activities that may be discussed may not be executable and, thus, not entrustable in real life because they are either too big/require too much effort (e.g. removing a mountain) or require the efforts of many persons (e.g. building a skyscraper), such that entrustment of the activity to one individual is not useful or practical. However, leading a team to do a big job may be an entrustable activity. The use of entrustable and entrustability in EPAs have become powerful language as they succinctly capture what clinicians do (ten Cate, 2013), and what new generations of junior members of the profession must start to be entrusted with.
Some authors have taken these new words and have given them different meanings from what was originally intended. This is confusing, but language is a living thing and there is no authority that prohibits its modification. While not recommended, entrustability has been used to describe individuals instead of activities. Some authors have thus described trainees are either 'entrustable' or 'not yet entrustable', or even their behaviour as 'entrustable' or 'pre-entrustable' (Englander et al., 2014). This new application of the word entrustable is not necessary, since the word 'trustworthy' exists for description of individuals (ten Cate, 2014). However, since 'untrustworthy' is not a term you would want to use with junior trainees when they have not yet reached the threshold of entrustment – which has a totally different connotation - we understand why educators would choose to use (pre-)entrustable to label a trainee (instead of the activity). The preferred and recommended usage would be trainee 'readiness for entrustment' (or for indirect supervision or for unsupervised practice et cetera), rather than entrustability of a trainee (Wijnen-Meijer, 2013; Chen and ten Cate, 2018).
Finally, entrustability has been used to describe psychometric scales that focus on entrustment (Rekman et al., 2016). That is incorrect (or at least not its original intended) use. Scales that focus on entrustment, are better described as 'entrustment scales' or 'supervision scales' or a combination of those words (entrustment/supervision scales). See also FAQ#12.
ten Cate, O. (2005) ‘Entrustability of professional activities and competency-based training’, Medical Education, 39(12), pp. 1176–1177. https://doi.org/10.1111/j.1365-2929.2005.02341.x.
ten Cate, O. (2013) ‘Competency-Based Education, Entrustable Professional Activities, and the Power of Language’, Journal of Graduate Medical Education, 5(1), pp. 6–7. https://doi.org/10.4300/JGME-D-12-00381.1.
ten Cate, O. (2014) ‘Trusting Graduates to Enter Residency: What Does It Take?’, Journal of Graduate Medical Education, 6(1), pp. 7–10. https://doi.org/10.4300/JGME-D-13-00436.1.
Chen, H. C. and ten Cate, O. (2018) ‘Assessment through Entrustable Professional Activities’, in Learning and Teaching in Clinical Contexts: A Practical Guide. 2nd edn. Chatswood: Elsevier Health Sciences.
Englander, R., Flynn, T., Call, S., Carraccio, C., et al. (2014) Core Entrustable Professional Activities for Entering Residency - Curriculum Developers Guide. Washington DC. Available at: https://members.aamc.org/eweb/upload/core%20EPA%20Curriculum%20Dev%20Guide.pdf (Accessed: 28 February 2019).
Rekman, J., Gofton, W., Dudek, N., Gofton, T., et al. (2016) ‘Entrustability Scales: Outlining Their Usefulness for Competency-Based Clinical Assessment’, Academic Medicine, 91(2), p. 186. https://doi.org/10.1097/ACM.0000000000001045.
Wijnen-Meijer, M. (2013) Readiness for clinical practice: studies about transitions in medical education, the influence of vertically integrated curricula and the assessment of readiness for practice [doctoral dissertation]. Available at: http://dspace.library.uu.nl/handle/1874/263142 (Accessed: 27 February 2019).