Introduction

Headache is one of the most common symptoms worldwide. This systematic review aimed to assess the effectiveness and safety of bloodletting therapy (BLT) for primary headache.

Methods

Four English databases, four Chinese databases and five trials registries were searched from inception to 2^nd Sep 2022. Randomized controlled trials which compared BLT to no treatment or drugs for primary headache were included. BLT as adjunctive treatment of drugs or acupuncture was also included. Two authors extracted data and assessed the quality of trials through the Cochrane risk of bias tool 2.0 independently. Pain intensity was the primary outcome (e.g. Visual analogue scale, VAS). Meta-analysis (using RevMan 5.4.1) with random effect model was conducted when there was no serious statistical heterogeneity among trials (I²≤75 %). GRADE was used to assess the certainty of evidence.

Results

Seventeen trials involving 1123 participants were included. Types of BLT included pricking BLT, wet cupping and bloodletting puncture with plum-blossom needle. The most frequently used BLT acupoint was Tai Yang. Type of comparisons included BLT vs. drugs (n = 3), BLT plus drugs vs. drugs (n = 4) and BLT plus acupuncture vs. acupuncture (n = 10). All included trials were assessed as "high risk of bias". Results showed that BLT plus rizatriptan benzoate tablets was superior to drug alone in reducing VAS (Mean Difference (MD)=-2.07 cm, 95 % Confidence Interval (CI) -2.65 cm to -1.50 cm, P<0.00001) and increasing the number of patients with more than half pain relief (by 39 %). BLT plus acupuncture was superior to acupuncture alone (MD=-0.80 cm, 95 % CI -1.20 cm to -0.41 cm, P<0.00001) for pain relief. However, no difference was found between BLT and drugs on decreasing VAS. The certainty of the overall evidence is very low mainly due to the poor methodological quality and high heterogeneity among trials.

Conclusion

Very low certainty evidence suggests that BLT combined with acupuncture or drugs may be more effective in relieving pain of primary headache and other concomitant symptoms. Current evidence does not support confirmatory conclusions about the safety of BLT.

中文翻译：

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原发性头痛的放血疗法：随机对照试验的系统评价和荟萃分析

介绍

头痛是全世界最常见的症状之一。本系统评价旨在评估放血疗法（BLT）治疗原发性头痛的有效性和安全性。

方法

检索了从开始到 2022 年 9 月 2 日期间的 4 个英文数据库、4 个中文数据库和 5 个试验注册中心。^纳入了比较 BLT 与不治疗或不使用药物治疗原发性头痛的随机对照试验。BLT 作为药物或针灸的辅助治疗也包括在内。两位作者通过 Cochrane 偏倚风险工具 2.0 独立提取数据并评估试验质量。疼痛强度是主要结果（例如视觉模拟量表，VAS）。当试验间不存在严重的统计异质性（ I≤75 %）时，采用随机效应模型进行荟萃分析（使用RevMan 5.4.1） 。GRADE 用于评估证据的确定性。

结果

其中包括 17 项试验，涉及 1123 名参与者。培根疗法的类型包括刺培培根疗法、湿拔罐法和梅花针放血疗法。最常用的 BLT 穴位是太阳穴。比较类型包括 BLT 与药物 ( n  = 3)、BLT 加药物与药物 ( n  = 4) 以及 BLT 加针灸与针灸 ( n  = 10)。所有纳入的试验均被评估为“高偏倚风险”。结果显示，BLT加苯甲酸利扎曲普坦片在降低VAS（平均差（MD）=-2.07 cm，95%置信区间（CI）-2.65 cm至-1.50 cm， P <0.00001）和增加数量方面优于单独药物。超过一半的患者疼痛得到缓解（39%）。BLT 联合针灸在缓解疼痛方面优于单独针灸（MD=-0.80 cm，95 % CI -1.20 cm 至 -0.41 cm，P <0.00001）。然而，BLT 和药物在降低 VAS 方面没有发现差异。总体证据的质量非常低，主要是由于方法学质量差和试验之间的异质性高。

结论

极低质量的证据表明，BLT 结合针灸或药物可能更有效地缓解原发性头痛和其他伴随症状的疼痛。目前的证据不支持关于 BLT 安全性的验证性结论。