The Cochrane Hepato-Biliary Group, Copenhagen Trial Unit, Center for Clinical Intervention Research, Department 7812, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark; Department of Internal Medicine, Ospedale A. Manzoni, Lecco, Italy.
Hepatology. 2014 Jul;60(1):408-18. doi: 10.1002/hep.26948.
The diagnostic research process can be divided into five phases, designed to establish the clinical utility of a new diagnostic test--the index test. The aim of the present review is to illustrate the study designs that are appropriate for each diagnostic phase, using clinical examples regarding liver fibrosis diagnosed with transient elastography, when possible. Phase 0 is the preclinical pilot phase during which the validity, reliability, and reproducibility of the index test are assessed in healthy and diseased people. Phase I is designed to describe the distribution of the index test results in healthy people and its normal values. Phase IIA comprises studies designed to estimate the accuracy (sensitivity and specificity) of the index test in discriminating between diseased and nondiseased people in a clinically relevant population. Phase IIB studies allow the comparison of the accuracy of different index tests; Phase IIC studies aim to evaluate the possible harms of incorporating the index test in a diagnostic-therapeutic strategy. In phase III, diagnostic test-therapeutic randomized clinical trials aim to assess the benefits and harms of the new diagnostic-therapeutic strategy versus the present strategy. Phase IV comprises large surveillance cohort studies that aim to assess the effectiveness of the new diagnostic-therapeutic strategy in clinical practice.
As common in clinical research, giving excessive weight to the results of single studies and trials is likely to divert from the totality of evidence obtained through the systematic reviews of these studies, conducted with rigorous methodology and statistical methods. (Hepatology 2014;60:408-418).
诊断研究过程可分为五个阶段，旨在确定新诊断测试（指标测试）的临床效用。本综述的目的是举例说明适用于每个诊断阶段的研究设计，尽可能使用关于通过瞬时弹性成像诊断肝纤维化的临床示例。第 0 阶段是临床前试点阶段，在此阶段评估健康人群和患病人群中指标测试的有效性、可靠性和可重复性。第 I 阶段旨在描述健康人群中指标测试结果的分布及其正常值。第 IIA 阶段包括旨在估计指标测试在临床相关人群中区分患病和非患病人群的准确性（敏感性和特异性）的研究。第 IIB 阶段的研究允许比较不同指标测试的准确性；第 IIC 阶段的研究旨在评估将指标测试纳入诊断-治疗策略的可能危害。在第 III 阶段，诊断测试-治疗随机临床试验旨在评估新的诊断-治疗策略与现有策略相比的益处和危害。第 IV 阶段包括大型监测队列研究，旨在评估新的诊断-治疗策略在临床实践中的有效性。
与临床研究一样，过于重视单一研究和试验的结果可能会偏离通过系统综述这些研究获得的整体证据，这些研究采用了严格的方法学和统计方法。（Hepatology 2014;60:408-418）。
