Gold S, Arndt S, Johnson D, O'Leary D S, Andreasen N C
Department of Psychiatry, University of Iowa, Iowa City 52242-1057, USA.
Neuroimage. 1997 May;5(4 Pt 1):280-91. doi: 10.1006/nimg.1997.0268.
The PET literature is growing exponentially, creating a need and an opportunity to perform a meta-analytic review consolidating the published information. This study describes the use of effect size as an index in PET studies and discusses how this measure can be used for comparing findings across studies, laboratories, and paradigms. In comparing studies across laboratories it is essential to know how the methods employed affect the results and conclusions drawn. This study also compared effect size for two different methods of tracer delivery in 15O PET studies ([15O]H2O bolus injection versus inhalation of [15O]CO2), whether averaged versus single-scan conditions were used, and the data analytic strategy employed. The effect sizes observed across studies were consistently large with a median effect size of 8.55, indicating that the phenomena investigated in 15O PET studies are strong. The largest peak activation reported in a study was found to be affected by variability in sample size, data analytic strategy, and repeat versus single-scan conditions. However, the impact of these factors was not examined on smaller or less intense peaks. Minimal standards for reporting statistical results are discussed.
正电子发射断层扫描（PET）的文献数量呈指数级增长，因此有必要也有机会进行一项荟萃分析综述，整合已发表的信息。本研究描述了效应量作为PET研究指标的应用，并讨论了该指标如何用于比较不同研究、实验室和范式的研究结果。在比较不同实验室的研究时，了解所采用的方法如何影响结果和得出的结论至关重要。本研究还比较了15O PET研究中两种不同示踪剂给药方法（[15O]H2O团注注射与吸入[15O]CO2）的效应量，无论采用的是平均条件还是单次扫描条件，以及所采用的数据分析策略。各研究中观察到的效应量始终很大，中位数效应量为8.55，表明15O PET研究中所研究的现象很显著。研究发现，一项研究中报告的最大峰值激活受样本量、数据分析策略以及重复扫描与单次扫描条件差异的影响。然而，这些因素对较小或强度较低的峰值的影响并未进行研究。本文还讨论了报告统计结果的最低标准。
