Sample size calculation and sampling technique
The sample size was calculated using the G*Power Windows 3.1.9.7 program, with a power of 0.88, an effect size of 0.25, and an alpha error probability of 0.05. Based on the calculation, This study required an a priori sample size of 81 intern nurses randomly selected from the four hospitals using Research Randomizer version 4.0 after considering a 20% loss ratio of follow-up (Hospital A = 35, hospital B = 20, hospital C = 11, hospital D = 15 intern nurses). Using a computer-generated randomization list, the participants were randomly assigned to either the intervention or control group in a 1:1 allocation ratio. The researchers concealed the allocation sequence until the participants were assigned to their respective groups. An independent statistician (one of the study authors) performed all randomization procedures and was blinded to the other authors until intervention procedures were completed. The statistician tried to match the control group as accurately as possible regarding age, gender, and working hour duration.