Gjørup T
Department of Internal Medicine, Sundby Hospital, Copenhagen, Denmark.
Acta Obstet Gynecol Scand Suppl. 1997;166:9-14.
The reliability of a diagnostic test depends on the accuracy and reproducibility of the test results. The accuracy is defined by comparing the test results with a final true diagnosis. The predictive values are here the most important clinical measures. Since it may be impossible to establish a final true diagnosis the reliability must in some cases be measured by a determination of reproducibility. The reproducibility is measured by comparing results of repeated examinations of the same patient. The reproducibility is measured by the use of the kappa coefficient which adjusts the observed agreement for expected chance agreement. A study of reliability of a diagnostic test should fulfill the same methodological requirements as other clinical studies. Both the predictive values and the kappa coefficient are supposed to depend on the prevalence and this should be noticed when results of different studies are compared. Reliability of diagnostic tests is often poor and scientific development of how to improve clinicians' diagnostic practice is much needed.
诊断试验的可靠性取决于试验结果的准确性和可重复性。准确性是通过将试验结果与最终的真实诊断进行比较来定义的。预测值是这里最重要的临床指标。由于可能无法确定最终的真实诊断，在某些情况下，可靠性必须通过确定可重复性来衡量。可重复性是通过比较对同一患者进行重复检查的结果来衡量的。可重复性是通过使用kappa系数来衡量的，该系数会根据预期的偶然一致性对观察到的一致性进行调整。对诊断试验可靠性的研究应满足与其他临床研究相同的方法学要求。预测值和kappa系数都应该取决于患病率，在比较不同研究的结果时应注意这一点。诊断试验的可靠性往往较差，非常需要关于如何改进临床医生诊断实践的科学发展。
