Acupuncture or Acupressure at the Sanyinjiao (SP6) Acupoint for the Treatment of Primary Dysmenorrhea: A Meta-Analysis

Table 1

Characteristics of acupuncture trials identified in the literature search.

First author, year; (location)	Number of participants	Intervention	Control	Assessment	Outcomes
Shi, 2011 [19](China)	40	Electroacupuncture at SP6 for 30 min	Electroacupuncture at unrelated acupoint (GB39), electroacupuncture at nonacupoint, and no electroacupuncture	Pain assessed by VAS before and after intervention	There were significant differences in VAS scores between the SP6 and no acupuncture groups after intervention (24.7 versus 48.2, 𝑃<0.05). There were no significant differences in VAS scores between the 3 acupuncture groups
Liu, 2011 [17] (China)	200	Electroacupuncture at SP6 for 30 min for 2 menstrual cycles	Electroacupuncture at unrelated acupoint (GB39), electroacupuncture at nonacupoint, and no electroacupuncture	Pain assessed by VAS before intervention, 5, 10, 30 min during intervention, and 30 min after intervention	The mean decrease in VAS score was significantly greater in all acupuncture groups compared with the no acupuncture group (SP6: −15.56, 𝑃<0.05; GB39: −18.14, 𝑃<0.05; nonacupoint: −10.96,  𝑃<0.05); There were no significant differences in VAS scores between the 3 acupuncture groups
Ma, 2010 [18] (China)	52	Electroacupuncture at SP6 for 10 min on day 1, 30 min on days 2 and 3	Electroacupuncture at unrelated acupoint (GB39), electroacupuncture at nonacupoint, and no electroacupuncture	Pain assessed by VAS before intervention, 5, 10, and 30 min after intervention	There were significantly greater reductions in VAS scores in the SP6 group compared with the other groups at each time after intervention (all 𝑃<0.05)
Yu, 2010 [20] (China)	66	Manual acupuncture at SP6 for 5 min	Manual acupuncture at unrelated acupoint (GB39)	Pain assessed before and after intervention according to dysmenorrhea score criteria	The pain score significantly decreased after intervention in the SP6 group (before = 11.20 versus after = 8.17, 𝑃<0.05), but not in the GB39 group

VAS: visual analogue scale.