Short-term low back pain relief with placebo

Référence

Kleine-Borgmann J, Schmidt K, Hellmann A, Bingel U. Effects of open-label placebo on pain, functional disability, and spine mobility in patients with chronic back pain: a randomized controlled trial. Pain 2019;160(12):2891–2897.

Sommaire

These authors enrolled 127 patients with long-term low back pain – more than 70% of enrollees reported having back pain for more than 5 years. The average age was approximately 59 years and 60% were women. Initial pain scores were approximately 5 out of a possible 10 and roughly 20% of the patients were treated with analgesics at the time of enrollment. The patients were told, before enrollment, that the study would involve placebo treatment and were shown a video on the beneficial effects of placebo. They were then randomized, with allocation assignment unconcealed, to receive existing care or existing care plus placebo (Zeebo) to be taken twice daily for 21 days. The patients were told it was placebo. At the end of the study, a composite pain intensity score—comprising minimum, maximum, and average pain intensities during the last 7 days on an 11-point scale—dropped more with placebo treatment than with existing care alone (0.62 vs 0.11; P = .001), and subjective disability scores improved to a greater extent with placebo (3.21 decrease vs 0.65 increase; P = .02). Objective mobility or anxiety and stress scores were not affected. I wish the researchers would have masked the enrolling investigator to the treatment assignment at the time of enrollment (concealed allocation); randomization produced an imbalance in body mass index between the groups, which might have been due to chance or to selective enrollment of patients.