Study design and participants
psychiatric
This study used a randomized controlled trial (RCT) design with a 1:1 ratio. Participants were employees of a combined cycle power plant in Iran. The company had 211 employees at the time of the study, all employees worked one of two teams, each working rotating 12-h shifts. Inclusion criteria were having more than one year of job tenure, no history of stress management education, and no history of psychiatric treatment, determined through participants’ self-report. Exclusion criteria included absence from two educational sessions, not attending the pre-test or post-test sessions, withdrawal from the study, and undergoing treatment by a psychiatrist due to mental illness during the intervention. 194 employees were eligible to participate, however some declined to participate leaving a consenting sample of 170 employees. A sample size calculation was calculated based on the effect size (0.58) provided by Faryabi et al.Data was collected at baseline, and three months after the 6-weeks educational intervention period had been completed. All participants completed the anonymous study questionnaires on the same day at baseline, and the same day at the follow-up, except for three participants in the intervention group who did not provide data at the three-month follow-up. This gave a final sample for data analysis of 103 participants. Figure Consort flow diagram of the study. 211 employees who participants worked one of two 12-hour shifts in an industrial plant were invited into the study. 170 gave informed consented. One shift was randomly allocated as the educational intervention group the other was the control group. From potential participants 53 participants were randomly allocated into each study group. Three participants dropped out of the Intervention Group before the three-months post-intervention follow-up which was on the same day for both groups. Thus, data was analysed from 50 participants in the Intervention group and compared with 53 participants in the control group.