Researchers from the University of Melbourne and St Vincent's Hospital, in Melbourne, Australia, evaluated the efficacy of pre-operative mind-body based interventions on post-operative outcomes with elective surgical patients.

A systematic review of the published literature was conducted using the electronic databases MEDLINE, CINAHL and PsychINFO. Randomized controlled trials (RCTs) with a prospective before-after surgery design were included.

Twenty studies involving 1297 patients were included. Mind-body therapies were categorized into relaxation, guided imagery and hypnotic interventions. The majority of studies did not adequately account for the risk of bias thus undermining the quality of the evidence.
Relaxation was assessed in eight studies, with partial support for improvements in psychological well-being measures, but a lack of evidence for beneficial effects for analgesic intake and length of hospital stay.

Guided imagery was examined in eight studies, with strong evidence for improvements in psychological well-being measures and moderate support for the efficacy of reducing analgesic intake.
Hypnosis was investigated in four studies, with partial support for improvements in psychological well-being measures.

Evidence for the effect of mind-body therapies on physiological indices was limited, with minimal effects on vital signs, and inconsistent changes in endocrine measures reported.

The review concludes that the quality of evidence for the efficacy of mind-body therapies for improving post-surgical outcomes is limited, but with strongest benefits coming from guided imagery.  Recommendations were made for future RCTs.

Nelson EA, Dowsey MM, Knowles SR, Castle DJ, Salzberg MR, Monshat K, Dunin AJ, Choong PF. Systematic review of the efficacy of pre-surgical mind-body based therapies on post-operative outcome measures. Complementary Therapies in Medicine. 2013 Dec;21 (6):pages 697-711.