Effects of mindfulness-based stress reduction on psychological distress in health workers: A three-arm parallel randomized controlled trial

Mindfulness-based Stress Reduction (MBSR) has shown good efficacy for improving wellbeing in employees experiencing occupational stress. However, comparisons with other interventions, longer-term follow-up, and data from varying sociocultural contexts are lacking. This three-arm, parallel randomised controlled trial (RCT) examined the effects of MBSR on psychological distress in non-physician health workers in direct contact with patients. 105 participants were randomly allocated to either: (1) MBSR (N = 35), (2) Stress Management Course (SMC; N = 34) or (3) wait-list (N = 36). Participants and those assessing outcomes were blinded to group assignment. Participants completed questionnaires pre- and post-intervention and four months after the intervention. Psychological distress was measured using the General Health Questionnaire (GHQ-12) and Outcome Questionnaire (OQ-45). Secondary outcomes included perceived stress, job satisfaction, mindfulness skills and changes in salivary cortisol. 77 participants completed measures post-intervention and 52 at 4-month follow-up. MBSR showed a post-intervention effect in reducing GHQ-12 (ss = -0.80 [SE = 1.58] p < 0.01) and OQ-45 (ss = -0.72, [SE = 5.87] p < 0.05) psychological distress, compared to SMC and in reducing GHQ-12 (ss = -1.30 [SE = 1.38] p < 0.001) and OQ-45 (ss = -0.71, [SE = 5.58] p < 0.01) psychological distress compared to wait-list condition. In our secondary outcome, only MBSR was associated with a decrease in the cortisol awaking response by 23% (p < 0.05). At follow-up, only effects of MBSR on the psychological distress 'social role' subscale (ss = -0.76 [SE = 1.31] p < 0.05) remained significant, compared to SMC. In conclusion, MBSR appears useful in reducing short-term psychological distress in healthcare workers, but these effects were not maintained at followup. Trial registration: ISRCTN12039804.