Chen, P.Y., Liu, Y.M., & Chen, M.L. (2017). The effect of hypnosis on anxiety in patients with cancer: A meta-analysis. Worldviews on Evidence-Based Nursing, 14, 223–236.

STUDY PURPOSE: To synthesize the evidence regarding immediate and sustained effects of hypnosis on anxiety in patients with cancer

TYPE OF STUDY: Meta analysis and systematic review

DATABASES USED: Scopus, Medline, PsycINFO, Academic Search Premier, CINAHL, and SDOL

INCLUSION CRITERIA: Hypnosis used as intervention, children or adults with cancer, sufficient data for meta analysis, anxiety was an outcome variable

EXCLUSION CRITERIA: Hypnosis combined with another psychological intervention, comparison of different types of hypnosis

TOTAL REFERENCES RETRIEVED: 1,483

EVALUATION METHOD AND COMMENTS ON LITERATURE USED: Assessment of quality based on the Cochrane guidelines for RCTs. 13 studies were RCTs and 7 were quasi-experimental design

FINAL NUMBER STUDIES INCLUDED: 20 

TOTAL PATIENTS INCLUDED IN REVIEW: 878

SAMPLE RANGE ACROSS STUDIES: 25-87

KEY SAMPLE CHARACTERISTICS: The majority of studies were in breast cancer survivors; 6 studies were in children

Across all 20 studies, the immediate effect size was significant in favor of hypnosis (Hedges g = 1.05, p < 0.01). There was also significant heterogeneity. The sustained effect size was also significant in favor of hypnosis (Hedges g = 1.69, p < 0.01) across five studies. Heterogeneity for sustained effects was also significant. Hypnosis was more effective when it combined therapist delivery with self-hypnosis than self-hypnosis only. Higher effect sizes were seen in studies of children, with procedure-related anxiety and studies with RCT design. Analysis suggested publication bias, and showed that smaller studies tended to report more positive results. With adjustment for bias, the effect size was reduced from 1.05 to 0.46.

Hypnosis can be beneficial to manage anxiety among patients with cancer. Therapist delivered alone or in combination with self-hypnosis was more effective than self-hypnosis alone.

• Limited number of studies included
• High heterogeneity
• Low sample sizes
• Varied timing, method of delivery and measurement of outcomes. Sample was too small to do relevant subgroup analyses

Hypnosis may be a helpful intervention to manage anxiety in adults and children with cancer for short- and long-term effects. Therapist involvement was more effective than self-hypnosis alone. For patients with significant anxiety, this may be an intervention to be considered.