Páez Borda A, Coba J M, Murillo N, Fernández P, de la Cal M A, Martín Osés E, Luján Galán M, Berenguer Sánchez A
Servicio de Urología, Hospital Universitario de Getafe, Madrid.
Actas Urol Esp. 1999 Jun;23(6):477-82.
To establish the reliability of three cystopathologists for cytological diagnosis of primary bladder tumors.
Pre-operative voided urine specimens of 71 patients with bladder cancer and 55 healthy controls were retrospectively and blindly reviewed by 3 independent cytologists, and their results--positive for bladder cancer, negative or inconclusive--were compared with each other. The estimation of the interobserver agreement was calculated using the weighted kappa-coefficient (k). A multivariative analysis was carried out to identify the factors associated with the disagreement among the three observers. The sensitivity and specificity for each of the participants were calculated in order to clearly identify the origin of the disagreement, in terms of the performance of the diagnostic test in the hands of each observer. A comparison of the overall diagnostic performance was made by plotting sensitivity versus 1-specificity.
The weighted k coefficient among observers was 0.46. The multivariative analysis did not identify any variable that could have caused such disagreement. Large differences in sensitivity and specificity were detected between observer number 1 (sens., 0.90, spec., 0.45) and observers number 2 (sens., 0.67, spec., 0.72) and number 3 (sens., 0.71, spec., 0.80), but the overall diagnostic performance (sensitivity vs 1-specificity) was superimposable in the three cases (p = ns).
Simple, reproducible and agreed-on diagnostic criteria should be established to yield reliable results in a group of cytologists. The consideration of individual diagnostic performances can give a false idea of homogeneity between observers. In this field, concordance analysis makes quality control reliable and should be a routine procedure of any pathology department.
确立三位膀胱病理学家对原发性膀胱肿瘤进行细胞学诊断的可靠性。
对71例膀胱癌患者和55例健康对照者的术前排尿尿液标本进行回顾性分析，并由3位独立的细胞学家进行盲法检查，将他们的结果（膀胱癌阳性、阴性或不确定）相互比较。采用加权kappa系数（k）计算观察者间一致性估计值。进行多变量分析以确定与三位观察者之间分歧相关的因素。计算每位参与者的敏感性和特异性，以便根据每位观察者手中诊断测试的表现明确分歧的来源。通过绘制敏感性与1-特异性的关系图对总体诊断性能进行比较。
观察者之间的加权k系数为0.46。多变量分析未发现任何可能导致这种分歧的变量。在观察者1（敏感性为0.90，特异性为0.45）与观察者2（敏感性为0.67，特异性为0.72）和观察者3（敏感性为0.71，特异性为0.80）之间检测到敏感性和特异性存在较大差异，但在三种情况下总体诊断性能（敏感性与1-特异性）是重叠的（p =无显著性差异）。
应建立简单、可重复且一致认可的诊断标准，以便在一组细胞学家中获得可靠结果。考虑个体诊断性能可能会给观察者之间的同质性带来错误认识。在该领域，一致性分析使质量控制可靠，应成为任何病理科的常规程序。
