Karger Ralf, Donner-Banzhoff Norbert, Müller Hans-Helge, Kretschmer Volker, Hunink Myriam
Institute for Transfusion Medicine and Haemostaseology, Philipps University, Marburg, Germany.
Platelets. 2007 Jun;18(4):249-60. doi: 10.1080/09537100601100366.
The Platelet Function Analyzer (PFA-100) is increasingly being used in the workup of patients with a bleeding diathesis. A profound knowledge of the possible diagnostic performance of this test is essential in order to make sound clinical decisions based on its results. It was the aim of this study to systematically review the published literature and provide valid estimates of the diagnostic performance of the PFA-100 for detecting disorders of primary haemostasis in newly presenting patients with a bleeding diathesis. A comprehensive literature search was performed for studies published between January 1994 and February 2006. Studies were eligible for the systematic review if they provided data supposed to be applicable to the determination of the diagnostic performance of the PFA-100. Furthermore, they were included in a meta-analysis if study reporting allowed calculation of sensitivity and specificity and if study quality ensured minimized biases of these estimates for the described clinical setting. Pooled weighted sensitivity, specificity and diagnostic odds ratio were calculated applying random effects modelling and constructing summary operator characteristic curves. This was done separately for the available test modifications using either collagen/epinephrine (PFA-EPI) or collagen/adenosine-diphosphate (PFA-ADP) for platelet activation. Thirty-six articles were included in the systematic review. Six studies met our eligibility criteria for a meta-analysis. The major reason for exclusion from the meta-analysis was a case-control design. A total of 1486 and 1259 patients were included in the meta-analysis of the diagnostic performance of the PFA-EPI and PFA-ADP, respectively. Pooled weighted sensitivity and specificity of the PFA-EPI/PFA-ADP in detecting a disorder of primary haemostasis were: 82.5/66.9% (95%-confidence interval (95%-CI): 76.0-88.9%/57.9-75.9%), and 88.7/85.5% (95%-CI: 84.3-93.1%/82.0-89.1%). 83/75% of patients with a positive PFA-EPI/PFA-ADP result do have a disorder of primary haemostasis whereas 88/79% with a negative PFA-EPI/PFA-ADP result do not. The PFA-EPI appeared to have a higher sensitivity and better predictive values than the PFA-ADP in detecting disorders of primary haemostasis, although a rigorous gold standard definition for a disorder of primary haemostasis, particularly for platelet disorders, was not applied in most studies. The majority of the studies lacked important requirements for quality and reporting, precluding a more precise and definitive characterization of the clinical utility of the PFA-100. This emphasizes the need for an evidence-based critical appraisal of diagnostic studies in haemostasis research in order to promote the conducting of studies that produce clinically relevant results.
血小板功能分析仪（PFA - 100）越来越多地用于对有出血素质患者的检查。为了根据该测试结果做出合理的临床决策，深入了解其可能的诊断性能至关重要。本研究的目的是系统回顾已发表的文献，并对PFA - 100检测新出现的有出血素质患者原发性止血障碍的诊断性能提供有效的评估。对1994年1月至2006年2月发表的研究进行了全面的文献检索。如果研究提供的数据适用于确定PFA - 100的诊断性能，则该研究符合系统评价的条件。此外，如果研究报告允许计算敏感性和特异性，并且研究质量确保在所描述的临床环境中这些估计值的偏差最小化，则将其纳入荟萃分析。应用随机效应模型并构建汇总算子特征曲线来计算合并加权敏感性、特异性和诊断比值比。这分别针对使用胶原蛋白/肾上腺素（PFA - EPI）或胶原蛋白/二磷酸腺苷（PFA - ADP）进行血小板活化的现有测试方法进行。36篇文章纳入了系统评价。6项研究符合我们荟萃分析的纳入标准。未纳入荟萃分析的主要原因是病例对照设计。分别有1486例和1259例患者纳入了PFA - EPI和PFA - ADP诊断性能的荟萃分析。PFA - EPI/PFA - ADP检测原发性止血障碍的合并加权敏感性和特异性分别为：82.5/66.9%（95%置信区间（95%-CI）：76.0 - 88.9%/57.9 - 75.9%），以及88.7/85.5%（95%-CI：84.3 - 93.1%/82.0 - 89.1%）。PFA - EPI/PFA - ADP结果为阳性的患者中83/75%确实存在原发性止血障碍，而结果为阴性的患者中88/79%不存在。在检测原发性止血障碍方面，PFA - EPI似乎比PFA - ADP具有更高的敏感性和更好的预测价值，尽管大多数研究未应用针对原发性止血障碍，特别是血小板疾病的严格金标准定义。大多数研究缺乏质量和报告方面的重要要求，这使得无法对PFA - 100的临床实用性进行更精确和明确的描述。这强调了在止血研究中对诊断研究进行基于证据的批判性评估的必要性，以促进开展能产生临床相关结果的研究。
