Department of Healthcare Economics and Quality Management, School of Public Health, Kyoto University Graduate School of Medicine, Yoshida Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan.
AJR Am J Roentgenol. 2009 Dec;193(6):1596-602. doi: 10.2214/AJR.08.2223.
Previous studies of the sensitivity and specificity of MRI in the diagnosis of meniscal tear have not included correction for verification bias. The purpose of this study was to investigate the extent to which verification bias affected assessment of the utility of MRI in the diagnosis of meniscal tear.
The patients included in the study were outpatients who from April 2006 through July 2008 consecutively visited a single institution for MRI of the meniscus for evaluation of knee pain. For patients who underwent arthroscopy in addition to MRI, the sensitivity and specificity of MRI were calculated. Global sensitivity analysis of data on patients who did not undergo arthroscopy was performed to estimate the influence of verification bias. Global sensitivity analysis is a method for graphically determining whether a particular pair of sensitivity and specificity estimates is compatible with observed data.
Eighty-two patients (23%) underwent arthroscopic verification. The sensitivity and specificity of MRI were 85% and 31%. When the possibility of meniscal tears in patients who did not undergo arthroscopy was subjected to global sensitivity analysis, the sensitivity of MRI ranged from 29% to 95% and the specificity ranged from 3% to 92%. All combinations of sensitivity and specificity produced a butterfly-shaped curve, but the base case was not inside the curve.
Verification bias greatly affected assessment of the utility of MRI in the diagnosis of meniscal tear. Sensitivity and specificity from previous studies may be incompatible with our data owing to verification bias.
先前研究半月板撕裂的 MRI 诊断的敏感性和特异性并未校正验证偏倚。本研究旨在探讨验证偏倚在多大程度上影响 MRI 诊断半月板撕裂的效用评估。
本研究纳入的患者为 2006 年 4 月至 2008 年 7 月连续就诊于单一机构行 MRI 检查以评估膝关节疼痛的门诊患者。对于行 MRI 检查后又行关节镜检查的患者，计算 MRI 的敏感性和特异性。对未行关节镜检查的患者进行数据的总体敏感性分析，以评估验证偏倚的影响。总体敏感性分析是一种通过图形确定特定敏感性和特异性估计值是否与观察到的数据相兼容的方法。
82 例患者（23%）行关节镜验证。MRI 的敏感性和特异性分别为 85%和 31%。当对未行关节镜检查的患者的半月板撕裂可能性进行总体敏感性分析时，MRI 的敏感性范围为 29%至 95%，特异性范围为 3%至 92%。所有敏感性和特异性组合均产生蝴蝶形曲线，但基础病例不在曲线内。
验证偏倚极大地影响了 MRI 诊断半月板撕裂的效用评估。由于验证偏倚，先前研究中的敏感性和特异性可能与我们的数据不相符。
