Henschke C I, Whalen J P
Department of Radiology, New York Hospital-Cornell University Medical College, New York 10021.
Clin Imaging. 1994 Oct-Dec;18(4):248-54. doi: 10.1016/0899-7071(94)90002-7.
Tests for pulmonary embolism (PE) and its most frequent source, deep vein thrombosis, include angiography, ventilation-perfusion nuclear medicine scans, and contrast and radionuclide venography. Although selective angiography is the definitive procedure for diagnosis of PE, its risk of death, although small, as well as the morbidity associated with contrast injections, is high enough that alternative, less accurate but safer, diagnostic procedures are preferred. Part I of this report described the methodology for selection of the single test having the lowest effective cost based on the test cost, its risks, and diagnostic performance. Other than the pulmonary angiogram, however, no single test has a sufficiently high diagnostic performance to be clinically realistic: incorrect diagnoses can result in sudden death. Sequences of tests or algorithms can be used to lower the overall risk of the tests to patients while increasing correct decision making to reach a clinically acceptable level. These points are illustrated by comparing three commonly recommended algorithms for the diagnosis of PE. Additionally, the prevalence of PE affects the choice of the algorithm, and we found that no single algorithm is best for all values of prevalence. In summary, we found that the most cost-effective strategy was to select the particular algorithm having the lowest effective cost for the relevant prevalence value. Use of algorithms also decreased the overall risk of diagnostic test complications and the number of incorrect diagnoses.
肺栓塞（PE）及其最常见来源——深静脉血栓形成的检测方法包括血管造影、通气-灌注核医学扫描以及造影剂和放射性核素静脉造影。尽管选择性血管造影是诊断PE的决定性方法，但其死亡风险虽小，但与造影剂注射相关的发病率较高，因此更倾向于选择其他准确性稍低但更安全的诊断方法。本报告的第一部分描述了基于检测成本、风险和诊断性能选择有效成本最低的单一检测方法的方法。然而，除了肺血管造影外，没有单一检测方法具有足够高的诊断性能以符合临床实际情况：错误诊断可能导致猝死。可以使用检测序列或算法来降低检测对患者的总体风险，同时提高正确决策水平，以达到临床可接受的程度。通过比较三种常用的推荐PE诊断算法可以说明这些要点。此外，PE的患病率会影响算法的选择，我们发现没有一种算法对所有患病率值都是最佳的。总之，我们发现最具成本效益的策略是为相关患病率值选择有效成本最低的特定算法。使用算法还降低了诊断测试并发症的总体风险和错误诊断的数量。
