The retrieval process was conducted systematically in four phases. In the first phase, 925 abstracts found in
MEDLINE or CINAHL were examined against the inclusion/exclusion criteria by two researchers working
independently. They discussed the results and decided which abstracts would be analysed further. A total of
174 possible studies based on abstracts met the inclusion/exclusion criteria. The remaining 707 were
excluded from the review. At this stage, 44 duplicates were excluded, leaving 130 abstracts. In the second
phase of the review, the two researchers re-examined the abstracts, focussing on the concepts under study:
106 studies were selected at this stage, which included two concept analyses and two reviews. A total of 24
abstracts were excluded because they did not focus on ethical concepts. This result was confirmed by a third
researcher.
In the third phase of the review, the full texts of the remaining 106 articles were reviewed independently
by three researchers. At the end of this phase, 35 articles were excluded because: four articles used samples