Krummenauer Frank
Institut für Medizinische Biometrie, Epidemiologie und Informatik der Universität Mainz.
Klin Monbl Augenheilkd. 2003 Apr;220(4):281-3. doi: 10.1055/s-2003-38633.
The evaluation of a new diagnostic or imaging device has to focus both on its diagnostic validity and reliability. Cohen's kappa coefficient can be used to assess the agreement of the new device's findings with those of an established diagnostic reference, it therefore presents a surrogate measure of validity. Additional measures of validity are sensitivity and specificity, which assess the order of agreement with the reference for positive and negative reference findings, respectively. The latter, however, can only be applied for binary reference findings. If discordant findings are observed, the McNemar test can be used to detect a diagnostic shift between diagnostic novum and reference. The estimation of reliability can be based on the independent parallel rating of a patient subset by two clinical readers; again the kappa coefficient measures the agreement of the parallel ratings and therefore represents a surrogate measure of reliability. The McNemar test can be used to detect an observer bias.
对新的诊断或成像设备的评估必须同时关注其诊断有效性和可靠性。科恩kappa系数可用于评估新设备的检查结果与既定诊断参考结果的一致性，因此它是有效性的一种替代指标。有效性的其他指标是敏感性和特异性，它们分别评估与阳性和阴性参考结果的一致程度。然而，后者仅适用于二元参考结果。如果观察到不一致的结果，可使用麦克尼马尔检验来检测新诊断方法与参考方法之间的诊断差异。可靠性的评估可以基于两名临床阅片者对患者子集的独立平行评级；同样，kappa系数衡量平行评级的一致性，因此代表可靠性的一种替代指标。麦克尼马尔检验可用于检测观察者偏差。
