Department of Radiology, University of Washington School of Medicine, UWMC Roosevelt Radiology, Seattle, WA 98105, USA.
Acad Radiol. 2011 Nov;18(11):1376-81. doi: 10.1016/j.acra.2011.06.014.
The sensitivity and specificity of magnetic resonance imaging (MRI) for diagnosis of meniscal tears has been studied extensively, with tears usually verified by surgery. However, surgically unverified cases are often not considered in these studies, leading to verification bias, which can falsely increase the sensitivity and decrease the specificity estimates. Our study suggests that such bias may be very common in the meniscal MRI literature, and illustrates techniques to detect and correct for such bias.
PubMed was searched for articles estimating sensitivity and specificity of MRI for meniscal tears. These were assessed for verification bias, deemed potentially present if a study included any patients whose MRI findings were not surgically verified. Retrospective global sensitivity analysis (GSA) was performed when possible.
Thirty-nine of the 314 studies retrieved from PubMed specifically dealt with meniscal tears. All 39 included unverified patients, and hence, potential verification bias. Only seven articles included sufficient information to perform GSA. Of these, one showed definite verification bias, two showed no bias, and four others showed bias within certain ranges of disease prevalence. Only 9 of 39 acknowledged the possibility of verification bias.
Verification bias is underrecognized and potentially common in published estimates of the sensitivity and specificity of MRI for the diagnosis of meniscal tears. When possible, it should be avoided by proper study design. If unavoidable, it should be acknowledged. Investigators should tabulate unverified as well as verified data. Finally, verification bias should be estimated; if present, corrected estimates of sensitivity and specificity should be used. Our online web-based calculator makes this process relatively easy.
磁共振成像（MRI）对半月板撕裂的诊断具有较高的敏感性和特异性，已有大量研究对此进行了验证，这些研究通常通过手术来验证撕裂的存在。然而，这些研究中往往并未纳入未经手术验证的病例，由此导致了验证偏倚，从而可能导致高估敏感性和低估特异性。我们的研究表明，这种偏倚在半月板 MRI 文献中可能非常普遍，并介绍了检测和校正这种偏倚的技术。
在 PubMed 中检索了评估 MRI 对半月板撕裂的诊断准确性的文章。如果研究纳入了任何未经手术验证的 MRI 结果的患者，则认为该研究存在潜在的验证偏倚。当可能时，进行了回顾性全局敏感性分析（GSA）。
从 PubMed 检索到的 314 篇研究中，有 39 篇专门涉及半月板撕裂。所有 39 篇研究均纳入了未经手术验证的患者，因此存在潜在的验证偏倚。仅有 7 篇文章提供了足够的信息进行 GSA。其中，1 篇研究显示存在明确的验证偏倚，2 篇研究显示无偏倚，其余 4 篇研究在某些疾病患病率范围内显示存在偏倚。仅有 39 篇中的 9 篇文章承认存在验证偏倚的可能性。
在发表的 MRI 对半月板撕裂的诊断准确性的敏感性和特异性评估中，验证偏倚被低估且可能很常见。在可能的情况下，应通过适当的研究设计来避免这种偏倚。如果无法避免，则应予以承认。研究者应列出经证实和未经证实的数据。最后，应评估验证偏倚的存在，如果存在，则应使用校正后的敏感性和特异性估计值。我们的在线网络计算器使这一过程相对简单。
