A four arm study published in the Archives of Internal Medicine 2009;169(9):827 showed that Acupuncture and supposed Sham Acupuncture were more than twice as effective as usual care. A total of 638 adults with chronic low back pain were randomized to individualized acupuncture (using TCM diagnosis), standardized acupuncture (same protocol for all), simulated acupuncture, or usual care.
Results from the study: At 8 weeks, mean dysfunction scores for the individualized, standardized, and simulated acupuncture groups improved by 4.4, 4.5, and 4.4 points, respectively, compared with 2.1 points for those receiving usual care (P < .001). Participants receiving real or simulated acupuncture were more likely than those receiving usual care to experience clinically meaningful improvements on the dysfunction scale (60% vs 39%; P < .001). Symptoms improved by 1.6 to 1.9 points in the treatment groups compared with 0.7 points in the usual care group (P < .001). After 1 year, participants in the treatment groups were more likely than those receiving usual care to experience clinically meaningful improvements in dysfunction (59% to 65% vs 50%, respectively; P = .02) but not in symptoms (P > .05).
Here's what you won't read in the abstract, that was found in this Time Magazine Article. The supposed "sham" group used toothpicks tapped through guide tubes to simulate Acupuncture.
A little history of Acupuncture. Back 2000-3000 years ago bian stones (or sharp rocks) and bamboo slivers (aka toothpicks) were used to stimulate the Acupuncture points because they didn't have needles. This study design essentially compared Ancient vs Modern Acupuncture, not Acupuncture and 'Sham'.