Publication dates offered further evidence that this was a newly emergent area of publication, with around 51% of all articles published after 2016 as shown in Figure 3 above. These preliminary searches were followed up by a focused series of searches.

Focused searching followed using keywords and search terms developed further from the core research questions and the top-level scoping. This subset of the literature was then examined against an inclusion/exclusion list. These focused searches formed the body of work for the next step, which was a narrative review of the key literature. These focused searches cover the timespan 1970-2022. This approach was applied to each of the topics identified above, as shown in Table 1 below: