The aims of the study are to determine the effectiveness of Mindfulness-Based Interventionas a workplace health promotion program on psychological distress, prolonged fatigue, job strain (job control and job demand), and perceived stress and to explore the influences of personal characteristics (including gender, age, education, and occupation) on the outcomes of the intervention with time.

This study was one component of the Taiwan Workplace Mental Health Promotion Scheme. The study adopted a study design of a randomized controlled trial. Two large-scale manufacturing factories were chosen for this study. All of the factories' 3270 full-time employees were requested to fill in a questionnaire comprising questions regarding mental health and job strain. Of these employees, 2849 individuals were willing to complete the questionnaire. A total of 431 employees (15.13%) were found to be in psychological distress with job strain. The screening procedure was carried out between June and July in 2011. A letter of invitation with an introduction to MBI was sent to these employees. Of these 431 employees, only 144 responded that they would be willing to take part voluntarily in the study. These 144 workers were allocated randomly into the intervention group (Group I, n=72) or the waiting-list control group (Group C, n=72).

All the participants were measured five times with an interval of four weeks between measurements. These measurements were taken at pre-intervention (T1), at mid-intervention (T2), at the completion of intervention (T3), four weeks after intervention (T4), and eight weeks after intervention (T5). The data related with the effectiveness of the intervention were obtained between August and December in 2011.

Inclusion Criteria:

• Healthy employees with psychological distress and job strain
• Full-time paid workers

Exclusion Criteria:

• Age < 18y or > 65y
• Part-time workers
• The workers are not willing to take part in the study