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1.
Objective:The National Library of Medicine (NLM) inaugurated a “publication type” concept to facilitate searches for systematic reviews (SRs). On the other hand, clinical queries (CQs) are validated search strategies designed to retrieve scientifically sound, clinically relevant original and review articles from biomedical literature databases. We compared the retrieval performance of the SR publication type (SR[pt]) against the most sensitive CQ for systematic review articles (CQrs) in PubMed.Methods:We ran date-limited searches of SR[pt] and CQrs to compare the relative yield of articles and SRs, focusing on the differences in retrieval of SRs by SR[pt] but not CQrs (SR[pt] NOT CQrs) and CQrs NOT SR[pt]. Random samples of articles retrieved in each of these comparisons were examined for SRs until a consistent pattern became evident.Results:For SR[pt] NOT CQrs, the yield was relatively low in quantity but rich in quality, with 79% of the articles being SRs. For CQrs NOT SR[pt], the yield was high in quantity but low in quality, with only 8% being SRs. For CQrs AND SR[pt], the quality was highest, with 92% being SRs.Conclusions:We found that SR[pt] had high precision and specificity for SRs but low recall (sensitivity), whereas CQrs had much higher recall. SR[pt] OR CQrs added valid SRs to the CQrs yield at low cost (i.e., added few non-SRs). For searches that are intended to be exhaustive for SRs, SR[pt] can be added to existing sensitive search filters. 相似文献
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Indexing consistency in MEDLINE 总被引：3，自引：0，他引：3
The quality of indexing of periodicals in a bibliographic data base cannot be measured directly, as there is no one "correct" way to index an item. However, consistency can be used to measure the reliability of indexing. To measure consistency in MEDLINE, 760 twice-indexed articles from 42 periodical issues were identified in the data base, and their indexing compared. Consistency, expressed as a percentage, was measured using Hooper's equation. Overall, checktags had the highest consistency. Medical Subject Headings (MeSH) and subheadings were applied more consistently to central concepts than to peripheral points. When subheadings were added to a main heading, consistency was lowered. "Floating" subheadings were more consistent than were attached subheadings. Indexing consistency was not affected by journal indexing priority, language, or length of the article. Terms from MeSH Tree Structure categories A, B, and D appeared more often than expected in the high-consistency articles; whereas terms from categories E, F, H, and N appeared more often than expected in the low-consistency articles. MEDLINE, with its excellent controlled vocabulary, exemplary quality control, and highly trained indexers, probably represents the state of the art in manually indexed data bases. 相似文献
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Douyère M Soualmia LF Névéol A Rogozan A Dahamna B Leroy JP Thirion B Darmoni SJ 《Health information and libraries journal》2004,21(4):253-261
The amount of health information available on the Internet is considerable. In this context, several health gateways have been developed. Among them, CISMeF (Catalogue and Index of Health Resources in French) was designed to catalogue and index health resources in French. The goal of this article is to describe the various enhancements to the MeSH thesaurus developed by the CISMeF team to adapt this terminology to the broader field of health Internet resources instead of scientific articles for the medline bibliographic database. CISMeF uses two standard tools for organizing information: the MeSH thesaurus and several metadata element sets, in particular the Dublin Core metadata format. The heterogeneity of Internet health resources led the CISMeF team to enhance the MeSH thesaurus with the introduction of two new concepts, respectively, resource types and metaterms. CISMeF resource types are a generalization of the publication types of medline. A resource type describes the nature of the resource and MeSH keyword/qualifier pairs describe the subject of the resource. A metaterm is generally a medical specialty or a biological science, which has semantic links with one or more MeSH keywords, qualifiers and resource types. The CISMeF terminology is exploited for several tasks: resource indexing performed manually, resource categorization performed automatically, visualization and navigation through the concept hierarchies and information retrieval using the Doc'CISMeF search engine. The CISMeF health gateway uses several MeSH thesaurus enhancements to optimize information retrieval, hierarchy navigation and automatic indexing. 相似文献
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Jane Harrison 《Health information and libraries journal》1997,14(1):33-42
Thepractice of evidence-based health care requires that information on methodology be identifiedfrom databases such as MEDLINE. Up until this year there have been no designated medicalsubject headings (MeSH) for evidence-based health care. ‘EVIDENCE-BASEDMEDICINE’ appears as a MeSH term from 1997. The absence of designated MeSH forthis concept prior to 1997 provides a challenge to the searcher. This paper describes the creationof a MEDLINE search strategy to retrieve articles on the methods of evidence-based health carepublished prior to the introduction of the new term, where an optimal combination of free-textand MeSH terms is required to identify relevant material. The study examines both free-text andsubject heading searching and attempts an optimal balance of sensitivity and specificity. It beginsby examining separate free-text and subject heading searches. Sensitivity of the subject headingsearch was 33% and specificity 80%, while the free-text search produced asensitivity of 50% and a specificity of 67%. The final strategy, combining bothapproaches, was more successful with sensitivity reaching between 82 and 90% andspecificity 83%. It is therefore possible to devise a search strategy to retrieve articles on themethods of evidence-based health care with relatively successful rates of sensitivity andspecificity. The limitations of MEDLINE, however, necessitate the use of additional approachesin identifying articles on the methods of evidence-based health care. 相似文献
6.
OBJECTIVE: To evaluate the adequacy of the MEDLINE instruction routinely given to all entering medical students at the University of Miami School of Medicine and the ability of students to search effectively for and retrieve evidence-based information for clinical decision making by the end of their third-year. METHODOLOGY: The authors developed and implemented a strategy for evaluating the search strategies and articles selected by third-year students, who participated in the Objective Structured Clinical Examination (OSCE) in June 1996, 1997, and 1998, and reviewed the literature on evidence-based medicine and evaluation of medical student searches. RESULTS: A mean of 5% of the students' search strategies and a mean of 26% of articles selected were ranked "excellent" or "good"; a mean of 26% of search strategies were ranked "fair" and a mean of 69% were ranked "poor"; and a mean of 22% of articles selected were ranked "fair" and a mean of 52% were ranked "poor" based on the strategy developed to evaluate student searches. CONCLUSIONS: Evaluating medical student searches for evidence-based information is an effective way of evaluating students' searching proficiency, and, in turn, the adequacy of the instruction they receive. Based on the results of the OSCE test, the school of medicine expanded the library's educational role and the library implemented major changes in the training program. Information on evidence-based medicine is now incorporated into the MEDLINE instruction. Library faculty evaluate the required searches performed by students for evidence-based information during their first and second years; 30% of students are identified for follow-up, individualized instruction based on the evaluation; and a new case-based curriculum has been proposed with a fourteen-week problem-based learning (PBL) block. These developments are timely in light of the evidence-based competencies recently published by the Association of American Medical Colleges. 相似文献
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《中国分类主题词表》的结构及功能评介张强Ａｂｓｔｒａｃｔ：Ｔｈｅ＂ＣｈｉｎｅｓｅＣｌａｓｓｉｆｉｅｄｓｕｂｊｅｃｔＴｈｅｓａｕｒｕｓ＂ｗｉｔｈｉｔｓｉｎｔｅｇｒａｔｉｏｎｏｆｃｌａｓｓｉｆｉｃａｔｉｏｎａｎｄｓｕｂｊｅｃｔｉｎｄｅｘｉｎｇｉｓＣｈｉｎ... 相似文献
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Content-based image retrieval in astronomy needs methods that can deal with an image content made of noisy and diffuse structures. This motivates investigations on how information should be summarized and indexed for this specific kind of images. The method we present first summarizes the image information content by partitioning the image in regions with same texture. We call this process texture summarization. Second, indexing features are generated by examining the distribution of parameters describing image regions. Indexing features can be associated with global or local image characteristics. Both kinds of indexing features are evaluated on the retrieval system of the Zurich archive of solar radio spectrograms. The evaluation shows that generating local indexing features using self-organizing maps yields the best effectiveness of all tested methods. 相似文献
10.
隐含语义检索及其应用 总被引：5，自引：1，他引：4
隐含语义检索(Latent Semantic Indexing, LSI) 是一种基于概念的文献检索方式。它区别于传统的基于用户查询条件与文档的单词匹配的文献检索方法, 根据文档与查询条件在语义上的关联而向用户提交查询结果。本文介绍了隐含语义检索在文献检索中的一种实现方法, 为文献检索提供了一种新的途径。 相似文献
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Bibliography of Bioethics and Index Medicus: comparison of coverage, publication delay, and ease of recall for journal articles on bioethics 总被引：1，自引：0，他引：1
S S Marsh 《Bulletin of the Medical Library Association》1987,75(3):248-252
Citations selected from the bibliographies of recent texts, a specialized subject bibliography, and review articles were checked in both Cumulated Index Medicus (IM) and the Bibliography of Bioethics (BB) to compare coverage, publication delay, probable causes of indexing and retrieval failure, and the ease with which relevant citations were retrieved. The study also attempted to determine whether BB included appropriate articles from the MEDLINE database in a timely and systematic manner. While 98% of the IM citations appeared within a year of publication, 79% of the BB citations appeared two to three years after their publication dates. The average citation appeared twice as frequently in IM as in BB. 相似文献
12.
Bibliographic retrievals on epilepsy prepared by MEDLARS and Excerpta Medica Foundation (EMF) monthly during 1968 were comparatively analyzed. EMF retrieved 1,116 citations with an average delay of 5.41 months, compared to 1,006 citations retrieved by MEDLARS with an average delay of 6.45 months. Differences in size of retrieval and delay between the systems were not significant. A total of 365 journals were represented, but a smaller group of ninety-one journals with citations in both retrievals formed a "core" of productive journals yielding over half the output of both systems. About 300 articles were cited in both searches, leaving 800 citations retrieved by EMF but not by MEDLARS and 700 citations retrieved by MEDLARS but not by EMF. Thus neither system was felt to provide comprehensive coverage of the epilepsy literature. Discrepancies in retrieval were found to be due primarily to indexing and retrieval procedures and not to coverage of different journals by the two systems. 相似文献
13.
单汉字标引技术的改进研究 总被引：10，自引：0，他引：10
王淼 《现代图书情报技术》1997,13(2):48-53
本文针对汉语构词的特殊性, 提出了一种单汉字标引的改进算法。该算法在标引上采用了对非检索词词首字的剔除标引, 在检索上, 采取检索词首字查找, 检索词直接匹配的算法。还提出了对检索结果的存储以及构筑后控词典, 以逐步完善单汉字检索系统。以上算法, 在SCIRS (Single Chinese Character Indexing and Retrieval System) 得到初步实现。 相似文献
14.
Background: Systematic review articles support the advance of science and translation of research evidence into healthcare practice. Inaccurate retrieval from medline could limit access to reviews. Objective: To determine the quality of indexing systematic reviews and meta‐analyses in medline . Methods: The Clinical Hedges Database, containing the results of a hand search of 161 journals, was used to test medline indexing terms for their ability to retrieve systematic reviews that met predefined methodologic criteria (labelled as ‘pass’ review articles) and reviews that reported a meta‐analysis. Results: The Clinical Hedges Database contained 49 028 articles; 753 were ‘pass’ review articles (552 with a meta‐analysis). In total 758 review articles (independent of whether they passed) reported a meta‐analysis. The search strategy that retrieved the highest number of ‘pass’ systematic reviews achieved a sensitivity of 97.1%. The publication type ‘meta analysis’ had a false positive rate of 5.6% (95% CI 3.9 to 7.6), and false negative rate of 0.31% (95% CI 0.26 to 0.36) for retrieving systematic reviews that reported a meta‐analysis. Conclusions: Inaccuracies in indexing systematic reviews and meta‐analyses in medline can be partly overcome by a 5‐term search strategy. Introducing a publication type for systematic reviews of the literature could improve retrieval performance. 相似文献
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This article provides a brief history of the development of the MEDLINE database and its huge impact within the UK, from its inception to the present time. The origins of MEDLINE can be traced back to a collection of books in the US Surgeon General's Office during the American Civil War and John Shaw Billings' decision, during 1867, to make this Library as complete as possible. From these beginnings, Index Medicus was developed in the early years of the 20th century, and electronic versions of the database began with the computerized on-demand search service MEDLARS in 1964 and then via CD-ROM and Internet Grateful Med to the web-based and free-to-all service, PubMed, in 1997. The response to PubMed was immediate and startling with usage increasing from 7 million searches per annum in 1996 to 400 million searches per annum in 2001 and the service continues to improve. MEDLINE providers are now offering mapping of natural language queries to the sophisticated indexing vocabulary (Medical Subject Headings, MeSH) and the provision of specific filters for different types of publication to improve searching efficiency, as well as links to full-text versions of the papers where available. The next steps are likely to involve an increased blurring of database and full-text boundaries, incorporating seamless access to the best available evidence within MEDLINE and a wide range of other information resources within a single search and to an increasing amount of full-text via various open-archive initiatives. As ever, the US National Library of Medicine is in the vanguard of research and further applications of its MEDLINE database for users within the UK will be awaited with great interest. 相似文献
16.
Background: Search filters can potentially improve the efficiency of searches involving electronic databases such as medline and embase . Although search filters have been developed for identifying records that contain adverse effects data, little is known about the sensitivity of such filters. Objectives: This study measured the sensitivity of using available adverse effects filters to retrieve papers with adverse effects data. Methods: A total of 233 included studies from 26 systematic reviews of adverse effects were used for analysis. Search filters from medline and embase were tested for their sensitivity in retrieving the records included in these reviews. In addition, the sensitivity of each individual search term used in at least one search filter was measured. Results: Subheadings proved the most useful search terms in both medline and embase . No indexing terms in medline achieved over 12% sensitivity. The sensitivity of published search filters varied in medline from 3% to 93% and in embase from 57% to 97%. Whether this level of sensitivity is acceptable will be dependent on the purpose of the search. Conclusions: Although no adverse effects search filter captured all the relevant records, high sensitivity could be achieved. Search filters may therefore be useful in retrieving adverse effects data. 相似文献
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OBJECTIVES: Indexing policy for the NHS Scotland e-Library needs to maximize future inter-operability with other significant health- and social-care-related resources. The strategic drive towards integration and partnership working means that the indexing system has to be widely acceptable to the full range of disciplines within the integrated health-care family. METHODS: Indexes identified by various means and then shortlisted using predefined criteria. RESULTS: Three subject indexes have been chosen--Medical Subject Headings (MeSH), CareData and the Government Category List (GCL), plus mapping between natural language and MeSH terms. This decision was a reasonable compromise between the strategy-driven aim of seamless access for all 'partners in care', and practical constraints of time/manpower. Other authority files (e.g. geographical area, language) are also standards based, and customised to reflect the information needs of an increasingly integrated health-care system. CONCLUSIONS: No single index could provide the scope required to meet the widening range of NHS information need. The influence of high-level strategic aims and objectives have extended their reach to influence indexing policy for the e-Library. Our indexing policy will continue to evolve and contribute to a knowledge management infrastructure capable of supporting current and future NHS Scotland information needs and strategy. Layperson terminology was identified as a gap; additional measures to address this gap are highlighted. 相似文献
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Latent Semantic Indexing (LSI) is a popular information retrieval model for concept-based searching. As with many vector space IR models, LSI requires an existing term-document association structure such as a term-by-document matrix. The term-by-document matrix, constructed during document parsing, can only capture weighted vocabulary occurrence patterns in the documents. However, for many knowledge domains there are pre-existing semantic structures that could be used to organize and categorize information. The goals of this study are (i) to demonstrate how such semantic structures can be automatically incorporated into the LSI vector space model, and (ii) to measure the effect of these structures on query matching performance. The new approach, referred to as Knowledge-Enhanced LSI, is applied to documents in the OHSUMED medical abstracts collection using the semantic structures provided by the UMLS Semantic Network and MeSH. Results based on precision-recall data (11-point average precision values) indicate that a MeSH-enhanced search index is capable of delivering noticeable incremental performance gain (as much as 35%) over the original LSI for modest constraints on precision. This performance gain is achieved by replacing the original query with the MeSH heading extracted from the query text via regular expression matches. 相似文献
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Nancy L. Wilczynski Cynthia Lokker Kathleen Ann McKibbon Nicholas Hobson R. Brian Haynes 《Journal of the Medical Library Association》2016,104(1):42-46
Objective
The research attempted to develop search filters for biomedical literature databases that improve retrieval of studies of clinical relevance for the nursing and rehabilitation professions.Methods
Diagnostic testing framework compared machine-culled and practitioner-nominated search terms with a hand-tagged clinical literature database.Results
We were unable to: (1) develop filters for nursing, likely because of the overlapping and expanding scope of practice for nurses in comparison with medical professionals, or (2) develop filters for rehabilitation, because of its broad scope and the profession''s multifaceted understanding of “health and ability.”Conclusions
We found limitations on search filter development for these health professions: nursing and rehabilitation. 相似文献20.
Ann Barrett Melissa Helwig Karen Neves 《Journal of the Medical Library Association》2016,104(2):118-124