To the Editor We have read with great interest the article by Petro and Rosen regarding the elegantly titled “Bouffant Scandal.”¹ In the era of evidence-based medicine, the heated debate about which surgical cap should adorn the heads of surgeons is, rather surprisingly, laden with nonscientific, sometimes petty and disingenuous arguments. The purpose of generating clinical practice guidelines is the promotion of an evidence-based delivery of health care and reduction of inappropriate variations in practice.² The process of guideline generation is not a straightforward one and, as we have shown,³ in complex diseases such as traumatic brain injury, the effort of generating meaningful guidelines may sometimes be hampered by the way evidence is translated into recommendations. Difficulties in translating evidence as well as a poor evidence base itself lead to volatile recommendations, with low survival from one edition of the guidelines to the other.³ In the preview of the Association of peri-Operative Registered Nurses (AORN) 2019 Guidelines, no recommendation could be made for the type of covers to be worn in restricted and semirestricted areas because the evidence does not demonstrate any association between the type of surgical head covering material or extent of hair coverage and surgical site infection (SSI) rates.¹ Formulating the recommendation in this manner seems to suggest that the evidence is lacking, which is not the case. A positive interpretation of the evidence would be to suggest that all of the studied surgical caps may be used because none shows a higher association to SSIs. Rather more worrisome is the recommendation that an interdisciplinary team, including members of the surgical team and infection preventionists, may determine the type of head covers that will be worn. The guideline committee has synthetized evidence, drawn conclusions, and formally recommends that another committee may redo this process, which suggests that different interpretations of the evidence may yield different results. Mechanistic reasoning (such as hair being contaminated with bacteria, which may increase the prevalence rate of SSI) has often been disproved when being tested in clinical trials and should not form the only basis of discounting the available studies.⁴ Mechanistic models are often too simplistic to apply in a clinical setting. Patient safety should always be paramount, but the enormous burden of administrative duties the modern surgeon faces⁵ may deter from this very objective, and guidelines should be, among others, a tool meant to ease this burden, not augment it.

致编辑我们非常感兴趣地阅读了Petro和Rosen的文章，标题为“ Bouffant Scandal”。^[1]在循证医学时代，关于哪种外科手术帽应修饰外科医师头部的激烈辩论令人惊讶地充满了不科学的观点，有时甚至是琐碎而虚假的论点。产生临床实践指南的目的是促进循证提供医疗保健，并减少实践中的不适当变化。²指南的制定过程不是一个简单的过程，正如我们所展示的，³在诸如颅脑外伤等复杂疾病中，有时会因将证据转化为建议的方式而妨碍制定有意义的指南的工作。难以翻译证据以及缺乏可靠的证据本身会导致推荐内容不​​稳定，从一版指南到另一版的生存期很短。³在《围手术期注册护士协会（AORN）2019年指南》的预览版中，对于在受限和半受限区域佩戴的床罩类型无法提出任何建议，因为证据表明手术类型之间没有任何关联头部覆盖物的材料或头发覆盖的程度以及手术部位感染（SSI）的比率。^1个以这种方式制定建议似乎表明缺乏证据，事实并非如此。对证据的正面解释是，建议使用所有已研究的手术帽，因为没有一个手术帽与SSI的关联性更高。更为令人担忧的是，建议由一个跨学科的团队（包括外科团队的成员和感染预防专家）来确定将要佩戴的头罩的类型。指导委员会已经综合了证据，得出了结论，并正式建议另一个委员会可以重做此过程，这表明对证据的不同解释可能会产生不同的结果。机械推理（例如头发被细菌污染，⁴机械模型通常过于简单，无法应用于临床。病人的安全永远是最重要的，但是现代外科医生要面对的巨大行政负担⁵可能会阻碍这一目标的实现，而指南尤其应是一种减轻这种负担而不是增加负担的工具。