Prescrire Int. 2016 Oct;25(175):247-250.
MedDRA (Medical Dictionary tor Regulatory Activities) is a standardised medical terminology, published by the International Council for Harmonisation, used in particular for coding cases of adverse effects in clinical study reports and pharmacovigilance databases, and to facilitate searches in these databases. MedDRA has a 5-level, hierarchical structure. Some levels are used to code adverse effects, and the others are designed to group together related terms for database searches. The links between these terms are hierarchical and complex. In addition to searches for terms, broad or narrow searches of MedDRA-coded databases can be performed using predefined "standardised Med-DRA queries", of which about a hundred are available in early 2016. A French study on 4 adverse effects recorded in France's national pharma- covigilance database showed that the effectiveness of MedDRA and stan- dardised MedDRA queries is highly variable, depending on the adverse effect examined. In some cases, less than half of the cases retrieved were relevant. A study on the adverse effects most frequently reported in clinical trials of 10 randomly selected drugs showed that a given adverse effect could be described using between 4 and several hundred different codes. One risk of fragmenting the reporting of adverse effects across multiple terms is that their true frequency will be underestimated. The development of a harmonised international terminology is a worth-while endeavour. But the complexity of MedDRA and its poorly evaluated performance make it susceptible to manipulation, errors of interpretation and bias. This applies in particular to the adverse effect statistics in the clinical study reports of clinical trials. The evaluation of the effectiveness of MedDRA as a tool for identifying and quantifying the adverse effects of new drugs must continue. For healthcare professionals, the limitations of MedDRA are one more reason to recognise that the known adverse effects of drugs, and their quantification, tend to be underestimated.
医学监管活动医学词典（MedDRA）是一种标准化医学术语，由国际协调理事会发布，尤其用于对临床研究报告和药物警戒数据库中的不良反应病例进行编码，并便于在这些数据库中进行检索。MedDRA具有五级层次结构。一些层级用于对不良反应进行编码，其他层级则旨在将相关术语归为一组以便在数据库中进行检索。这些术语之间的联系具有层级性且复杂。除了术语检索外，还可以使用预定义的“标准化MedDRA查询”对MedDRA编码的数据库进行广泛或精确检索，截至2016年初大约有一百个此类查询可用。一项针对法国国家药物警戒数据库中记录的4种不良反应的法国研究表明，MedDRA和标准化MedDRA查询的有效性差异很大，这取决于所研究的不良反应。在某些情况下，检索到的病例中不到一半是相关的。一项针对随机选择的10种药物临床试验中最常报告的不良反应的研究表明，一种特定的不良反应可能用4到数百个不同的代码来描述。将不良反应报告分散在多个术语中的一个风险是其真实频率会被低估。开发统一的国际术语是一项有价值的努力。但MedDRA的复杂性及其评估不佳的性能使其容易受到操纵、解释错误和偏差的影响。这尤其适用于临床试验临床研究报告中的不良反应统计。必须继续评估MedDRA作为识别和量化新药不良反应工具的有效性。对于医疗保健专业人员来说，MedDRA的局限性更是一个理由，让他们认识到药物已知的不良反应及其量化往往被低估。
