Long-lasting effect of penetrating acupuncture among responders: Double-blind RCT of acupuncture for vulvodynia.

Vulvodynia, vulvar pain of unknown etiology, lasting 3 months or longer, affects 7% of American women, and has no consistently effective treatment. We aimed to test the efficacy of acupuncture on vulvar pain and dyspareunia and explore the duration of the effect in a double-blind randomized controlled trial of acupuncture for vulvodynia. 89 women, 19-62 years old (mean 30.2 ± 8.3), 70% White, 20% Hispanic; 91% completed a 13-needle, 10-session standardized acupuncture protocol using double-blind acupuncture needles. Average Pain Intensity of vulvar pain (API, 0-10 scale) and dyspareunia (Female Sexual Function Index) were measured at baseline and after the 10th treatment. Participants with a clinically important post-treatment improvement reported weekly Tampon Test scores (0-10), a measure of provoked vulvar pain, until they returned to baseline. Percentage of responders was similar: acupuncture 58%, placebo 57%; no significant differences were found between acupuncture and placebo groups on API or dyspareunia upon completion of treatments. Responders showed a consistently higher rate of return to baseline pain during the 12-week post-treatment follow-up in the placebo group compared to the acupuncture group (hazard ratio: 2.72, 95% CI: 1.13-6.54). Effects of acupuncture on vulvodynia may have been underestimated because of the strong placebo response from the skin-touch placebo needles. Among responders, the relatively large placebo effect did not persist for as many participants as the therapeutic effect of penetrating acupuncture during the 12-week follow up. Findings indicate investigations into the effects among acupuncture responders and non-responders are warranted. Findings also merit larger, pragmatic trials. PERSPECTIVE: Double-blind RCT of acupuncture for vulvodynia tested vulvar pain and dyspareunia and explored the duration of effect. Penetrating acupuncture and skin-touch placebo needle groups had pain reduction, not significantly different between groups. Pain reduction lasted longer for significantly more responders in the penetrating acupuncture vs. skin-touch placebo groups.