Effectiveness and Safety of Acupuncture for Migraine: An Overview of Systematic Reviews

Migraine is a common neurological problem that affects millions of people around the world, characterized by intense, recurrent headaches frequently accompanied by nausea, vomiting, and sensitivity to light and sound. According to epidemiological data, the prevalence of migraine ranges from 3.3% to 32.6% in women and 0.7% to 16.1% in men. In the United States, this condition generates annual costs between $6.5 and $17 billion, representing a significant burden for both individuals and society. The 2010 Global Burden of Disease Study classified migraine as the third most prevalent disorder worldwide and the seventh leading specific cause of disability.

Conventional treatments include nonsteroidal anti-inflammatory drugs, antiepileptics, ergotamines, and triptans; however, these medications frequently cause undesirable side effects such as fatigue, sleep disturbances, nausea, and vomiting, leading many patients to seek nonpharmacological therapeutic alternatives.

This study aimed to critically evaluate the quality of existing systematic reviews on acupuncture for migraine and provide an objective and comprehensive assessment of the effectiveness and safety of this therapy. The researchers conducted an overview of systematic reviews, a methodology recognized for systematically collecting and reassessing high-quality scientific evidence on the same health problem. To this end, they conducted searches in eight major databases through December 2019, including MEDLINE, Embase, Cochrane Library, and Chinese databases, in addition to gray literature such as dissertations and conference reports. Two independent reviewers selected the studies following pre-established criteria, extracted the data, and assessed methodological quality using standardized tools.

Methodological quality was assessed through AMSTAR 2, risk of bias by ROBIS, reporting quality by PRISMA-A, and quality of evidence by the GRADE system.

The analysis included 15 systematic reviews published between 2011 and 2019, covering studies that involved between 2 and 33 randomized controlled trials each. The methodological assessment revealed that 14 of the 15 reviews were classified as critically low quality and only one as low quality by AMSTAR 2. Nine reviews presented low risk of bias according to ROBIS, and 11 reviews adequately met more than 70% of the PRISMA-A criteria. High-quality evidence demonstrated that acupuncture has a higher effectiveness rate than Western medications in the treatment of migraine.

In addition, acupuncture proved more effective in reducing the number of headache days, the use of analgesics, and was more effective in reducing the frequency and intensity of attacks compared with both medications and sham acupuncture. The safety analysis, performed in eight of the included reviews, indicated that acupuncture has fewer adverse events than conventional medications.

The clinical implications of this study are significant for both patients and healthcare professionals. The high-quality evidence suggests that acupuncture can be considered an effective and safe therapeutic option for the treatment of migraine, especially for patients who experience significant side effects from conventional medications or those seeking nonpharmacological approaches. For healthcare professionals, these results provide a solid scientific basis for considering acupuncture as part of the treatment plan for migraine, both for prevention and for acute relief of attacks. The superior safety of acupuncture relative to traditional medications is particularly relevant for patients who require long-term treatment or have contraindications to specific medications.

These findings may also inform public health policies and clinical guidelines, potentially contributing to the broader integration of acupuncture into health systems.

However, the study has important limitations that should be considered. The main limitation refers to the methodological quality of the systematic reviews analyzed, with the majority being classified as critically low quality. Identified problems include lack of pre-registered protocols, inadequate search strategies, insufficient assessment of publication bias, and limited analysis of heterogeneity among studies. In addition, the search was restricted to publications in English and Chinese, which may have resulted in the loss of relevant studies in other languages.

The inability to synthesize all the evidence due to data heterogeneity may have affected the precision of the conclusions. The authors also note that inconsistency among studies was the main cause of downgrading the quality of the evidence, often due to high statistical heterogeneity and overlapping confidence intervals. Despite these limitations, this study represents the first comprehensive assessment of the evidence on acupuncture for migraine using rigorous assessment tools, providing an important basis for future research and informed clinical decisions about this widely used complementary therapy.