Acupuncture is still effective for pain relief a year after treatment has ended, according to a paper by Prof Hugh MacPherson and international colleagues from the Acupuncture Trialists’ Collaboration. Using a large individual patient data set from high-quality randomised trials of acupuncture for chronic pain (20 trials, including 6376 patients) the authors determined the trajectory of pain scores over time, after acupuncture for conditions including musculoskeletal pain (low back, neck, shoulder), osteoarthritis of the knee and headache. In trials comparing acupuncture to a no-acupuncture control, effect sizes diminished by a nonsignificant amount (0.011 SD per three months) after treatment ended. This suggests that approximately 90 percent of the benefit of acupuncture relative to controls would be sustained at 12 months. For trials comparing acupuncture to sham, they observed a smaller, but still significant, reduction in effect size (0.025 SD per three months), suggesting approximately a 50 percent diminution at 12 months. The authors recommend that studies of the cost-effectiveness of acupuncture should take these findings into account.

The persistence of the effects of acupuncture after a course of treatment: a meta-analysis of patients with chronic pain. Pain. 2017 May;158(5):784-793.