The two-step Fagan's nomogram: ad hoc interpretation of a diagnostic test result without calculation.
The two-step Fagan's nomogram: ad hoc interpretation of a diagnostic test result without calculation.
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DOI：
10.1136/eb-2013-101243
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发表时间：
2013-08-01
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影响因子：
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通讯作者：
Vanderstichel, Raphael
中科院分区：
文献类型：
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作者：
Caraguel, Charles G B;Vanderstichel, Raphael
1975年，费根发表了一个列线图，帮助医生在不使用计算器或计算机的情况下，确定患者在特定测试结果下真正患有感兴趣疾病的概率。诺模图对于床边解释测试结果非常有用，因为没有测试是完美的。然而，费根诺模图的实用性是有限的，其使用的似然比（LR），一个参数不常报告的诊断试验的评价研究。LR反映了测试结果提供的证据的方向和强度，并且可以从测试的常规诊断灵敏度（DSe）和特异性（DSp）计算。费根的诺模图中没有这种初始计算，这使得它不适合日常使用。我们已经无缝集成了计算LR的初始步骤，由此产生的两步列线图允许用户快速解释测试结果。随着DSe和DSp的添加，用于解释二分测试结果的诺模图现在已经完成。该工具比原来的工具更容易使用和灵活，这将有助于在日常循证实践中使用。列线图可在www.adelaide.edu.au/vetsci/research/pub_pop/2step-nomogram/下载。
In 1975, Fagan published a nomogram to help practitioners determine, without the use of a calculator or computer, the probability of a patient truly having a condition of interest given a particular test result. Nomograms are very useful for bedside interpretations of test results, as no test is perfect. However, the practicality of Fagan's nomogram is limited by its use of the likelihood ratio (LR), a parameter not commonly reported in the evaluation studies of diagnostic tests. The LR reflects the direction and strength of evidence provided by a test result and can be computed from the conventional diagnostic sensitivity (DSe) and specificity (DSp) of the test. This initial computation is absent in Fagan's nomogram, making it impractical for routine use. We have seamlessly integrated the initial step to compute the LR and the resulting two-step nomogram allows the user to quickly interpret the outcome of a test. With the addition of the DSe and DSp, the nomogram, for the purposes of interpreting a dichotomous test result, is now complete. This tool is more accessible and flexible than the original, which will facilitate its use in routine evidence-based practice. The nomogram can be downloaded at: www.adelaide.edu.au/vetsci/research/pub_pop/2step-nomogram/.