Jordan J E, Donaldson S S, Enzmann D R
Department of Radiology, Stanford University School of Medicine, CA 94305-5105, USA.
Cancer. 1995 May 15;75(10):2579-86. doi: 10.1002/1097-0142(19950515)75:10<2579::aid-cncr2820751027>3.0.co;2-3.
This study was designed to investigate the costs associated with the use of magnetic resonance imaging (MRI) in the workup of spinal cord compression caused by metastatic disease, an area in which it has proven to be diagnostically useful.
The study was divided into two parts. Part 1 consisted of a retrospective review of the hospital charts of 46 patients, half of whom were diagnosed with cord compression in the pre-MRI era and the other half diagnosed after MRI availability; costs for these two groups were compared. Part 2 consisted of a review of several major studies comparing the sensitivities and specificities of MRI with alternative imaging techniques, usually myelography. Cost effectiveness and cost/cost ratios were derived for diagnostic usefulness using prevalence, sensitivity, specificity, and cost estimates of MRI and its alternatives, including costs of false-negative and false-positive testing.
Our hospital-based experience yielded an average cost of $ 3664 per patient without MRI and $ 2283 per patient when MRI was available (1991 dollar amounts). The cost of diagnosis was 65% more expensive without MRI. Use of the literature-based experience demonstrated that the cost of diagnosis was at least 82% more costly without MRI than when it was available. However, when key variables were altered during sensitivity analysis, this difference of increased cost of diagnosis without MRI ranged from 25% to 98%.
This work suggests that MRI may result in significant economic benefits in diagnosing metastatic cord compression, but further work is needed on physician behavior and referral patterns with MRI versus myelography as is long term follow-up for potential reductions in patient debility using MRI.
本研究旨在调查在转移性疾病所致脊髓压迫症的检查中使用磁共振成像（MRI）的相关成本，MRI在该领域已被证明具有诊断价值。
本研究分为两部分。第一部分包括对46例患者的医院病历进行回顾性分析，其中一半患者在MRI应用前被诊断为脊髓压迫症，另一半在有MRI检查后被诊断；比较这两组的成本。第二部分包括对几项主要研究的综述，这些研究比较了MRI与其他成像技术（通常是脊髓造影）的敏感性和特异性。利用MRI及其替代方法的患病率、敏感性、特异性和成本估计值，包括假阴性和假阳性检测的成本，得出诊断有用性的成本效益和成本/成本比。
我们基于医院的经验显示，在没有MRI时，每位患者的平均成本为3664美元，有MRI时为每位患者2283美元（以1991年美元金额计）。没有MRI时，诊断成本贵65%。利用基于文献的经验表明，没有MRI时的诊断成本比有MRI时至少贵82%。然而，在敏感性分析中改变关键变量时，没有MRI时诊断成本增加的差异范围为25%至98%。
这项研究表明，MRI在诊断转移性脊髓压迫症方面可能带来显著的经济效益，但在医生对MRI与脊髓造影的行为和转诊模式方面，以及对使用MRI可能降低患者虚弱程度的长期随访方面，还需要进一步研究。
