of Acupuncture Evidence-based Synthesis Program 11 The figure provides a broad visual overview over the evidence base. The bubble plot depicts the estimated research volume based on the number of acupuncture RCTs included in the largest review summarizing the clinical indication, the estimated treatment effect of acupuncture compared to passive control, and the confidence in the effect, judging from published systematic reviews. Estimates of the size of the treatment effect based on specific individual reviews as well as reason for classifying the evidence base as inconclusive are reported in the narrative synthesis. The evidence map used the clinical topics as addressed in existing reviews, and individual research studies may have contributed to a number of included reviews and clinical indications. All 3 depicted dimensions (literature size, effect, and confidence) are estimates and can only provide a broad overview of the evidence base. EXECUTIVE SUMMARY: PAIN As shown in the bubble plot, a large number of studies have addressed the treatment of headaches with acupuncture; a 2008 review included 31 RCTs124 and 5 independent systematic reviews have been published since 2005. A Cochrane review on tension-type headache by Linde et al., last updated in 2009, reported that 3 to 4 months after randomization, the pooled responder rate ratio was 1.24 (95% confidence interval [CI]: 1.05, 1.46) with 50% responders in the acupuncture groups compared to 41% in sham groups across 4 RCTs.120 The review concluded that acupuncture could be a valuable non-pharmacological tool in patients with frequent episodic or chronic tension-type headaches. A 2012 individual patient data meta-analysis published by Vickers et al for the Acupuncture Trialists’ Collaboration included data from 29 RCTs evaluating acupuncture for chronic pain. 47 The review reported that patients receiving acupuncture had less pain, with scores that were 0.23 (95% CI: 0.13, 0.33), 0.16 (95% CI: 0.07, 0.25) and 0.15 (95% CI: 0.07, 0.24) standard deviations lower than sham controls for back and neck pain, osteoarthritis, and chronic headache. The review concluded that acupuncture is effective for the treatment of chronic pain and is a reasonable referral option. However, the most recent available best evidence syntheses concentrating on back pain, neck pain, or osteoarthritis individually do not summarize the evidence as equally unrestrictedly positive, as outlined further below. Thus, the conclusion that acupuncture had evidence of effectiveness with high confidence for chronic pain patients is currently still limited by the lack of conclusive evidence syntheses for the individual conditions that make up 50-65% of chronic pain, namely back pain and neck pain. There is considerable research available for migraine prophylaxis; a 2009 Cochrane review by the same author group working on headaches included 22 acupuncture RCTs.121 The review reported sufficient detail for a reanalysis and a positive effect across all passive controlled RCTs as defined in this review of reviews was identified. However, it should be noted that effects were driven by RCTs comparing acupuncture to no acupuncture (relative risk [RR] 2.33; 95% CI: 2.02, 2.69), not RCTs comparing acupuncture and sham (RR 1.13; 95% CI: 0.95, 1.35). The review concluded that acupuncture should be considered a treatment option for patients willing to undergo this treatment. More than half of the 7 included RCTs on chronic headaches included in the chronic pain IPD meta-analysis47 are also included in the Cochrane reviews on headaches and migraine. Dysmenorrhea has also been addressed in a large number of primary studies; a 2010 systematic review on primary dysmenorrhea included 27 RCTs.92 A Cochrane review on dysmenorrhea last Evidence Map of Acupuncture Evidence-based Synthesis Program 12 updated in 2012 reported an improvement in pain relief from acupuncture compared with placebo control (odds ratio [OR] 9.5, 95% CI: 21.17, 51.8) and concluded that acupuncture may reduce period pain but further well-designed RCTs are needed.72 Osteoarthritis has also been targeted in a large number of systematic reviews (we identified 6 recent reviews from independent author groups) and individual research studies; a 2012 Centre for Reviews and Dissemination (CRD) network meta-analysis on the relief of chronic pain due to osteoarthritis of the knee included 22 acupuncture RCTs.174 The report, comparing different physical treatments, concluded that acupuncture is one of a number of physical treatments that produces a clinically-relevant effect in alleviating pain in the short-term, and although further research is needed to substantiate these conclusions, acupuncture should be considered as an evidence-based treatment option for relieving pain due to osteoarthritis of the knee. A 2010 Cochrane review on acupuncture for peripheral joint osteoarthritis reported positive results for acupuncture in comparison to sham and waiting list control but not as add-on treatment compared to exercise-based physiotherapy alone. The review concluded that benefits compared to shame were small, did not meet predefined thresholds for clinical relevance, and were probably due at least partially to placebo effects from incomplete blinding, while effects compared to waiting list were