This study involved 71 forensic seized drug laboratories analyzing 65 total samples; 17 were ground-truth positive (i.e., they contained methamphetamine or cocaine); 48 were ground-truth negative (i.e., they did not contain methamphetamine or cocaine). The positive samples were prepared at several target-analyte concentrations and combined with common cutting agents. The negative samples were designed to be challenging and prepared to contain positional isomers of methamphetamine. Participants were sent two different sample sets. In the first, they were directed to only use a single, pre-selected analytical technique. In the second, they were directed to use a pre-selected analytical scheme consisting of multiple techniques in compliance with ASTM E2329-17. The results of the study showed good accuracy; sensitivity was 1.000 for all analytical schemes with 1-specificity (the false-positive rate) ranging from 0.000 to 0.250 when ASTM E2329-17 compliant analytical schemes were used. When only a single technique was used, accuracy was generally not as good; sensitivity ranged from 1.000 to 0.091, and 1-specificity ranged from 0.000 to 0.245.

中文翻译：

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对 ASTM E2329-17 甲基苯丙胺样品检获药物鉴定标准操作规程中的分析方案进行循证评估

这项研究涉及 71 个法医检获毒品实验室，分析了总共 65 个样本； 17 件经检验结果呈阳性（即含有甲基苯丙胺或可卡因）； 48 份的真实结果为阴性（即它们不含甲基苯丙胺或可卡因）。阳性样品以多种目标分析物浓度制备，并与常见的切割剂结合。阴性样品被设计为具有挑战性，并含有甲基苯丙胺的位置异构体。向参与者发送了两组不同的样本。首先，他们被要求仅使用单一的、预先选择的分析技术。在第二步中，他们被要求使用预先选定的分析方案，该方案由符合 ASTM E2329-17 的多种技术组成。研究结果显示出良好的准确性；当使用符合 ASTM E2329-17 的分析方案时，所有分析方案的灵敏度均为 1.000，1-特异性（假阳性率）范围为 0.000 至 0.250。当仅使用单一技术时，准确性通常不太好；敏感性范围为 1.000 至 0.091，1-特异性范围为 0.000 至 0.245。