Roy Pierre-Marie, Colombet Isabelle, Durieux Pierre, Chatellier Gilles, Sors Hervé, Meyer Guy
Emergency Department, Centre Hospitalier Universitaire, 49033 Angers cedex 01, France.
BMJ. 2005 Jul 30;331(7511):259. doi: 10.1136/bmj.331.7511.259.
To assess the likelihood ratios of diagnostic strategies for pulmonary embolism and to determine their clinical application according to pretest probability.
Medline, Embase, and Pascal Biomed and manual search for articles published from January 1990 to September 2003.
Studies that evaluated diagnostic tests for confirmation or exclusion of pulmonary embolism. DATA EXTRACTED: Positive likelihood ratios for strategies that confirmed a diagnosis of pulmonary embolism and negative likelihood ratios for diagnostic strategies that excluded a diagnosis of pulmonary embolism.
48 of 1012 articles were included. Positive likelihood ratios for diagnostic tests were: high probability ventilation perfusion lung scan 18.3 (95% confidence interval 10.3 to 32.5), spiral computed tomography 24.1 (12.4 to 46.7), and ultrasonography of leg veins 16.2 (5.6 to 46.7). In patients with a moderate or high pretest probability, these findings are associated with a greater than 85% post-test probability of pulmonary embolism. Negative likelihood ratios were: normal or near normal appearance on lung scan 0.05 (0.03 to 0.10), a negative result on spiral computed tomography along with a negative result on ultrasonography 0.04 (0.03 to 0.06), and a d-dimer concentration < 500 mug/l measured by quantitative enzyme linked immunosorbent assay 0.08 (0.04 to 0.18). In patients with a low or moderate pretest probability, these findings were associated with a post-test probability of pulmonary embolism below 5%. Spiral computed tomography alone, a low probability ventilation perfusion lung scan, magnetic resonance angiography, a quantitative latex d-dimer test, and haemagglutination d-dimers had higher negative likelihood ratios and can therefore only exclude pulmonary embolism in patients with a low pretest probability.
The accuracy of tests for suspected pulmonary embolism varies greatly, but it is possible to estimate the range of pretest probabilities over which each test or strategy can confirm or rule out pulmonary embolism.
评估肺栓塞诊断策略的似然比，并根据验前概率确定其临床应用。
检索Medline、Embase和Pascal Biomed数据库，并手工检索1990年1月至2003年9月发表的文章。
评估用于确诊或排除肺栓塞的诊断试验的研究。提取的数据：确诊肺栓塞的策略的阳性似然比和排除肺栓塞诊断的策略的阴性似然比。
1012篇文章中有48篇被纳入。诊断试验的阳性似然比为：高概率通气灌注肺扫描18.3（95%置信区间10.3至32.5），螺旋计算机断层扫描24.1（12.4至46.7），以及下肢静脉超声检查16.2（5.6至46.7）。在验前概率为中度或高度的患者中，这些结果与肺栓塞的验后概率大于85%相关。阴性似然比为：肺扫描正常或接近正常表现0.05（0.03至0.10），螺旋计算机断层扫描结果为阴性且下肢静脉超声检查结果为阴性0.04（0.03至0.06），以及通过定量酶联免疫吸附测定法测得的D-二聚体浓度<500μg/L 0.08（0.04至0.18）。在验前概率为低度或中度的患者中，这些结果与肺栓塞的验后概率低于5%相关。单独的螺旋计算机断层扫描、低概率通气灌注肺扫描、磁共振血管造影、定量乳胶D-二聚体试验和血凝D-二聚体具有较高的阴性似然比，因此仅能在验前概率低的患者中排除肺栓塞。
疑似肺栓塞检测的准确性差异很大，但可以估计每种检测或策略能够确诊或排除肺栓塞的验前概率范围。
