Presented at the 2013 AAPM Annual Meeting« Back

Assessing Dose and Practice Effects of Hypnosis for Chronic Low Back Pain

Gabriel Tan, PhD ABPP, psygt@nus.edu.sg¹, (1) National University of Singapore, Singapore

Introduction: The efficacy of self-hypnosis training for decreasing chronic pain intensity is well-established. However, little research has examined the "dose" (number of sessions) needed or the importance of practice outside of the session for maximizing treatment benefits. Methods: 100 patients with a history of moderate to severe chronic low back pain were randomized to one of four treatment conditions: Group 1: 8 sessions of face-to-face instruction on self–hypnosis without home practice, Group 2: 8 sessions of face-to-face instruction on self–hypnosis plus home practice, Group 3: 2 sessions of face-to-face instruction on self–hypnosis plus home practice, and Group 4: a biofeedback-assisted relaxation control condition. Results: Results indicated (1) a significantly greater treatment effect on pain intensity in the combined hypnosis group than in the control condition (p =.041, eta square = .042) and (2) large and significant reductions in both pain intensity and pain interference for all 3 hypnosis groups over time (pain intensity: p < .0001, η2 =.500; pain interference: p < .0001, η2 =.450). However, improvement was similar for the 3 hypnosis groups. Effect sizes (Cohen’s d for paired t-tests) for pre- to post-treatment effects for Groups 1, 2, and 3 were 0.810, 1.267, and 1.179, respectively, for pain intensity and 0.911, 1.012, and 0.889, respectively, for pain interference, all indicating large but similar effects. Conclusions: Pain reduction was not substantially increased by adding 6 additional sessions of hypnosis training after an initial 2 or by home practice. This was also found at 6 months follow-up.

Funding: VHA Rehabilitation Research and Development