Howard Kirsten, Lord Sarah J, Speer Anthony, Gibson Robert N, Padbury Robert, Kearney Brendon
School of Public Health, University of Sydney, New South Wales, Australia.
Int J Technol Assess Health Care. 2006 Winter;22(1):109-18. doi: 10.1017/s0266462306050902.
Endoscopic retrograde cholangiopancreatography (ERCP) is considered the gold standard for imaging of the biliary tract but is associated with complications. Less invasive imaging techniques, such as magnetic resonance cholangiopancreatography (MRCP), have a much lower complication rate. The accuracy of MRCP is comparable to that of ERCP, and MRCP may be more effective and cost-effective, particularly in cases for which the suspected prevalence of disease is low and further intervention can be avoided. A model was constructed to compare the effectiveness and cost-effectiveness of MRCP and ERCP in patients with a previous history of cholecystectomy, presenting with abdominal pain and/or abnormal liver function tests.
Diagnostic accuracy estimates came from a systematic review of MRCP. A decision analytic model was constructed to represent the diagnostic and treatment pathway of this patient group. The model compared the following two diagnostic strategies: (i) MRCP followed with ERCP if positive, and then management based on ERCP; and (ii) ERCP only. Deterministic and probabilistic analyses were used to assess the likelihood of MRCP being cost-effective. Sensitivity analyses examined the impact of prior probabilities of common bile duct stones (CBDS) and test performance characteristics. The outcomes considered were costs, quality-adjusted life years (QALYs), and cost per additional QALY.
The deterministic analysis indicated that MRCP was dominant over ERCP. At prior probabilities of CBDS, less than 60 percent MRCP was the less costly initial diagnostic test; above this threshold, ERCP was less costly. Similarly, at probabilities of CBDS less than 68 percent, MRCP was also the more effective strategy (generated more QALYs). Above this threshold, ERCP became the more effective strategy. Probabilistic sensitivity analyses indicated that, in this patient group for which there is a low to moderate probability of CBDS, there was a 59 percent likelihood that MRCP was cost-saving, an 83 percent chance that MRCP was more effective with a higher quality adjusted survival, and an 83 percent chance that MRCP had a cost-effectiveness ratio more favorable than dollars 50,000 per QALY gained.
Costs and cost-effectiveness are dependent upon the prior probability of CBDS. However, probabilistic analysis indicated that, with a high degree of certainty, MRCP was the more effective and cost-effective initial test in postcholecystectomy patients with a low to moderate probability of CBDS.
内镜逆行胰胆管造影术（ERCP）被认为是胆道成像的金标准，但会引发并发症。侵入性较小的成像技术，如磁共振胰胆管造影术（MRCP），并发症发生率要低得多。MRCP的准确性与ERCP相当，并且MRCP可能更有效且具有成本效益，特别是在疾病疑似患病率较低且可避免进一步干预的情况下。构建了一个模型，以比较MRCP和ERCP在有胆囊切除病史、出现腹痛和/或肝功能检查异常的患者中的有效性和成本效益。
诊断准确性评估来自对MRCP的系统评价。构建了一个决策分析模型来代表该患者群体的诊断和治疗路径。该模型比较了以下两种诊断策略：（i）先进行MRCP检查，若结果为阳性则接着进行ERCP检查，然后根据ERCP结果进行治疗；（ii）仅进行ERCP检查。采用确定性分析和概率分析来评估MRCP具有成本效益的可能性。敏感性分析考察了胆总管结石（CBDS）的先验概率和检查性能特征的影响。所考虑的结果包括成本、质量调整生命年（QALYs）以及每增加一个QALY的成本。
确定性分析表明MRCP优于ERCP。在CBDS的先验概率低于60%时，MRCP是成本较低的初始诊断检查；高于此阈值时，ERCP成本较低。同样，在CBDS概率低于68%时，MRCP也是更有效的策略（产生更多的QALYs）。高于此阈值时，ERCP成为更有效的策略。概率敏感性分析表明，在这个CBDS概率为低到中等的患者群体中，MRCP有59%的可能性节省成本，有83%的可能性更有效且具有更高质量调整后的生存率，有83%的可能性其成本效益比优于每获得一个QALY 50,000美元。
成本和成本效益取决于CBDS的先验概率。然而，概率分析表明，在高度确定性下，对于CBDS概率为低到中等的胆囊切除术后患者，MRCP是更有效且具有成本效益的初始检查。
