In the second part, the nurse experts had to rate each risk factor according to its predictive power for determining vulnerability to DCO. Responses were scored on a Likert scale ranging from 1 to 5, which means that the higher the score, the greater the representativeness of the risk factor. In addition, for each conceptual definition presented for each risk factor, experts were asked to assess how well each definition described the corresponding nursing phenomenon. Each conceptual definition for the risk factors received a score: +1, 0 or −1, equivalent to ‘adequate’, ‘somewhat adequate’ or ‘inadequate’.