Five studies (in eight publications) were included in the review (n=1,823): one uncontrolled prospective cohort (four publications), two uncontrolled pre-post studies, one prospective non-randomised comparison study and one descriptive study with a control group. Methodological quality ranged from poor to good.
The cohort study reported a number of results for changes in outcomes between 0 and 12 months. One paper where EYT was received by 94 per cent of patients for a median of 119 days reported significant improvement of disease scores (ES 1.70, 95% CI: 1.47, 1.99, large effect) and symptom scores (ES 1.27, 95% CI: 1.08, 1.50, large effect) and for quality of life scores (SF-36 and KITA , ES 0.41 to 0.67 respectively). Adverse reactions to EYT occurred in three per cent of participants, but none were severe enough to discontinue treatment. Two other publications from the same study reported significant improvements for disease scores (ES of 1.23 and 1.52) and symptom scores (ES 1.09 and 1.04) together with improvement in quality of life scores (data not reported) for EYT. The final article reported a significant improvement in scores for disease (ES 1.77), symptom scores (ES 0.91), quality of life (1.11) and depression (ES 1.20).
One uncontrolled pre-post study reported significant improvements in BMI in girls with anorexia nervosa aged 10 to 13 years (ES 1.02, 95% CI: 0.26, 2.45, large effect), 14 to 16 years (ES 0.99, 95% CI 0.31, 1.57, large effect), and 17 to 19 years (ES 0.22, 95% CI: -1.00, 1.32, small effect). The other with an uncontrolled pre-post study of five boys reported positive changes for various symptoms relating to ADHD.
One prospective non-randomised study reported a significant improvement from 0 to 12 months for symptom scores for chronic low back pain for both the EYT group (ES 1.00, 95% CI: 0.33, 1.67, large effect) and for conventional therapy group (ES 0.57, 95% CI: 0.02, 1.3, moderate effect). A second prospective controlled study reported no significant differences between EYT and control groups for psychological and psychomental reactions.