*2.1. Design*

An observational single-group cross-sectional study was conducted. The participants were nursing students of 13 Spanish universities in all years of the degree. In Spain, the degree in nursing has a duration of four years and the students carry out clinical placements in health institutions from the second year onwards. Data collection was anonymous and did not entail any academic benefit for the students. Students were informed that participation was voluntary and that their involvement in the study would not affect their grade. We followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) [14]. All students received the instructions about the study by email with an information sheet and informed consent agreement. It was explained to them that their participation was anonymous, confidential and had no repercussions for the results.
