Johnson E D, Sievert M C, McKinin E J
J. Otto Lottes Health Sciences Library, University of Missouri-Columbia 65211, USA.
Proc Annu Symp Comput Appl Med Care. 1995:846-50.
It has been established that subject searches of medical full-text databases obtain higher recall than subject searches in a bibliographic database. In this study we attempted to determine if the same rule might apply when searching for a non-subject parameter such as study design. A simultaneous search of bibliographic and full-text records from the New England Journal of Medicine provided data on the number of items retrieved by each kind of search. Filtering strategies were created for 5 different study types: randomized controlled trials, other clinical trials and prospective studies, cohort studies, longitudinal and follow-up studies, and multicenter studies. The point of the study was to compare the numbers of items retrieved from the bibliographic database, MEDLINE, and those retrieved from the full-text version of NEJM, and to examine the unique access points available in each file. For all the study types the full-text file retrieved a larger number of records than MEDLINE, most of which were retrieved because of methodology terms found in the text but not in the title or abstract. In MEDLINE, descriptors and publication types, two value-added fields supplied by indexers, retrieved 11-89% more than title and abstract alone.
已经确定，在医学全文数据库中进行主题检索比在书目数据库中进行主题检索具有更高的召回率。在本研究中，我们试图确定在搜索诸如研究设计等非主题参数时，同样的规则是否适用。同时搜索《新英格兰医学杂志》的书目记录和全文记录，提供了每种搜索方式检索到的文献数量数据。针对5种不同的研究类型制定了筛选策略：随机对照试验、其他临床试验和前瞻性研究、队列研究、纵向和随访研究以及多中心研究。该研究的目的是比较从书目数据库MEDLINE中检索到的文献数量与从《新英格兰医学杂志》全文版本中检索到的文献数量，并检查每个文件中可用的独特检索点。对于所有研究类型，全文文件检索到的记录数量都比MEDLINE多，其中大部分是由于在文本中而非标题或摘要中找到的方法学术语而检索到的。在MEDLINE中，索引员提供的两个增值字段——描述符和出版物类型，比仅通过标题和摘要检索到的文献数量多11%-89%。
