Rasmussen L S, Larsen K, Houx P, Skovgaard L T, Hanning C D, Moller J T
Department of Anaesthesia, Centre of Head and Orthopaedics, Copenhagen University Hospital, Rigshospitalet, Denmark.
Acta Anaesthesiol Scand. 2001 Mar;45(3):275-89. doi: 10.1034/j.1399-6576.2001.045003275.x.
Postoperative cognitive function (POCD) has been subject to extensive research. In the literature, large differences are apparent in methodology such as the test batteries, the interval between sessions, the endpoints to be analysed, statistical methods, and how neuropsychological deficits are defined. Traditionally, intelligence tests or tests developed for clinical neuropsychology have been used. The tests for detecting POCD should be based on well-described sensitivity and suitability in relation to surgical patients. In tests using scores, floor/ceiling effects may compromise the evaluation if the tests are either too easy or to difficult. Uncontrolled testing facilities and change of test personnel may affect the test performance. Practice effects are pronounced in neuropsychological tests but have generally been ignored. The use of a suitable normative population is essential to allow correction for practice effects and variability between sessions. Missing follow-up may severely compromise valid conclusions since subjects unable or unwilling to be examined are particularly prone to suffer from POCD. In the statistical analysis of the test results, the evaluation should be based on differences between pre- and postoperative performance. Parametric statistical tests are not relevant unless the appropriate Gaussian distributions are present, perhaps after transformation of data. The definition of cognitive dysfunction should be restrictive and the criteria should be fulfilled in only a small proportion of volunteers. In the literature, these requirements often have not been fulfilled. This precludes a reasonable estimation of the incidence of POCD and the conclusions of comparative studies should be interpreted with great caution. In this review article, we present a number of recommendations for the design and execution of studies within this area. In addition, the critical reader may use these recommendations in the evaluation of the literature.
术后认知功能（POCD）已受到广泛研究。在文献中，诸如测试组合、测试时段之间的间隔、待分析的终点、统计方法以及神经心理学缺陷如何定义等方法存在明显差异。传统上，一直使用智力测试或为临床神经心理学开发的测试。检测POCD的测试应基于与手术患者相关的明确描述的敏感性和适用性。在使用分数的测试中，如果测试过于简单或过于困难，地板效应/天花板效应可能会影响评估。不受控制的测试设施和测试人员的更换可能会影响测试表现。练习效应在神经心理学测试中很明显，但通常被忽视。使用合适的正常人群对于校正练习效应和各时段之间的变异性至关重要。缺失随访可能会严重影响有效结论，因为无法或不愿意接受检查的受试者特别容易患POCD。在测试结果的统计分析中，评估应基于术前和术后表现的差异。除非存在适当的高斯分布（可能在数据转换后），否则参数统计测试不适用。认知功能障碍的定义应严格，并且标准应仅在一小部分志愿者中得到满足。在文献中，这些要求往往未得到满足。这妨碍了对POCD发生率的合理估计，并且比较研究的结论应极其谨慎地解释。在这篇综述文章中，我们提出了一些关于该领域研究设计和实施的建议。此外，批判性读者可以在评估文献时使用这些建议。
