Chowdhury Nilotpal, Pai Muktha R, Lobo Flora D, Kini Hema, Varghese Rebecca
Department of Pathology, Kasturba Medical College, Mangalore, India.
Anal Quant Cytol Histol. 2006 Aug;28(4):213-8.
To study random and the systematic error in breast cancer grading, to find the source of disagreements and measure the reliability of graders so that appropriate corrective action can be taken.
Five independent observers graded 50 breast carcinoma slides from 50 consecutive breast cancer specimens according to the Nottingham criteria. The polychoric correlation was used to measure association. Stuart-Maxwell and McNemar tests were used to measure equality of thresholds.
The polychoric correlation among observers was high (mean = 0.803, 0.712, 0.797 and 0.602 for the final grade, tubule formation, nuclear pleomorphism and mitotic figures, respectively). However, there were significant differences in thresholds (6, 7, 7 and 9 pairs of 10 showing significant differences in classification of grades/scores for final grade, tubule formation, nuclear pleomorphism and mitotic counts, respectively).
The high polychoric correlations suggest that random error in grading breast cancers in this study was low, confirming the underlying reliability of grading and graders. However, significant differences in the thresholds lowers raw agreement. Such a scenario may be rectified by increased intradepartmental discussion.
研究乳腺癌分级中的随机误差和系统误差，找出分歧来源并评估分级者的可靠性，以便采取适当的纠正措施。
五名独立观察者根据诺丁汉标准对来自50例连续乳腺癌标本的50张乳腺癌切片进行分级。采用多列相关来衡量相关性。使用斯图尔特 - 麦克斯韦检验和麦克尼马尔检验来衡量阈值的一致性。
观察者之间的多列相关性较高（最终分级、小管形成、核异型性和有丝分裂计数的平均相关性分别为0.803、0.712、0.797和0.602）。然而，阈值存在显著差异（最终分级、小管形成、核异型性和有丝分裂计数的分级/评分分类中，分别有6、7、7和9对呈现出显著差异）。
较高的多列相关性表明本研究中乳腺癌分级的随机误差较低，证实了分级及分级者的潜在可靠性。然而，阈值的显著差异降低了原始一致性。这种情况可通过加强部门内部讨论来纠正。
