PubMed, Internet Grateful Med, and Ovid: a comparison of three MEDLINE Internet interfaces

Three MEDLINE Internet interfaces are compared: PubMed, Internet Grateful Med, and Ovid MEDLINE. Although these interfaces all search MEDLINE, significant differences exist in terms of their search interfaces, presentation of results, and special features. This paper examines these variations and explores some of the advantages and disadvantages of the three interfaces.     

PubMed免费MEDLINE检索功能和使用方法

针对网上医学文献检索中的实际问题，介绍了美国国家医学图书馆生物技术中心开发的PubMed网站更新的免费MEDLINE检索功能和使用方法。     

A quiver full of arrows: recommended Web-based tutorials for PubMed,PowerPoint, Ovid MEDLINE,and FrontPage

Librarians often are responsible for instructing their patrons in the use of various databases and popular software packages. When this instruction can't be provided through face-to-face contact, Web-based tutorials can be useful tools to bridge the information gap. This article recommends Web-based tutorials for PubMed, Ovid MEDLINE, PowerPoint, and FrontPage.     

The NICE OECD countries' geographic search filters: Part 2—validation of the MEDLINE and Embase (Ovid) filters

Objective:We previously developed draft MEDLINE and Embase (Ovid) geographic search filters for Organisation for Economic Co-operation and Development (OECD) countries to assess their feasibility for finding evidence about the countries. Here, we describe the validation of these search filters.Methods:We identified OECD country references from thirty National Institute for Health and Care Excellence (NICE) guidelines to generate gold standard sets for MEDLINE (n=2,065) and Embase (n=2,023). We validated the filters by calculating their recall against these sets. We then applied the filters to existing search strategies for three OECD-focused NICE guideline reviews (NG103 on flu vaccination, NG140 on abortion care, and NG146 on workplace health) to calculate the filters'' impact on the number needed to read (NNR) of the searches.Results:The filters both achieved 99.95% recall against the gold standard sets. Both filters achieved 100% recall for the three NICE guideline reviews. The MEDLINE filter reduced NNR from 256 to 232 for the NG103 review, from 38 to 27 for the NG140 review, and from 631 to 591 for the NG146 review. The Embase filter reduced NNR from 373 to 341 for the NG103 review, from 101 to 76 for the NG140 review, and from 989 to 925 for the NG146 review.Conclusion:The NICE OECD countries'' search filters are the first validated filters for the countries. They can save time for research topics about OECD countries by finding the majority of evidence about OECD countries while reducing search result volumes in comparison to no filter use.     

The NICE OECD countries’ geographic search filters: Part 1—methodology for developing the draft MEDLINE and Embase (Ovid) filters

Objective:There are no existing validated search filters for the group of 37 Organisation for Economic Co-operation and Development (OECD) countries. This study describes how information specialists from the United Kingdom''s National Institute for Health and Care Excellence (NICE) developed and evaluated novel OECD countries’ geographic search filters for MEDLINE and Embase (Ovid) to improve literature search effectiveness for evidence about OECD countries.Methods:We created the draft filters using an alternative approach to standard filter construction. They are composed entirely of geographic subject headings and are designed to retain OECD country evidence by excluding non-OECD country evidence using the NOT Boolean operator. To evaluate the draft filters’ effectiveness, we used MEDLINE and Embase literature searches for three NICE guidelines that retrieved >5,000 search results. A 10% sample of the excluded references was screened to check that OECD country evidence was not inadvertently excluded.Results:The draft MEDLINE filter reduced results for each NICE guideline by 9.5% to 12.9%. In Embase, search results were reduced by 10.7% to 14%. Of the sample references, 7 of 910 (0.8%) were excluded inadvertently. These references were from a guideline about looked-after minors that concerns both OECD and non-OECD countries.Conclusion:The draft filters look promising—they reduced search result volumes while retaining most OECD country evidence from MEDLINE and Embase. However, we advise caution when using them in topics about both non-OECD and OECD countries. We have created final versions of the search filters and will validate them in a future study.     

Evaluation of a program to teach health professionals to search MEDLINE

This study analyzes the search behavior of end users who had taken a class in searching MEDLINE on the National Library of Medicine's MEDLARS system. Of the class alumni, 58% obtained passwords. Most of these were still conducting their own searches twelve to eighteen months later. Telephone interviews and search observations indicated that these end users were satisfied with their results and felt they had mastered the basic mechanics of searching. However, appropriate use of explodes and subheadings, as well as locating appropriate search terms, still presented difficulties for them. Further training in these areas may be required.     

The effect of CD-ROM MEDLINE on online end user and mediated searching.

Since 1970, Indiana University School of Medicine Library (IUSML) has traditionally been a high volume online searching institution. The library recently implemented an end user searching program which includes MEDLINE on CD-ROM. The effect of CD-ROM on online end user and mediated searching is discussed. Comparative statistics are provided by category of search service. CD-ROM has had a dramatic lowering effect on online end user searching and has had little effect on mediated searching. IUSML's experience with CD-ROM technology has been a positive one. Trained end users have become IUSML's greatest asset.     

Development of an efficient search filter to retrieve systematic reviews from PubMed

Objective:Locating systematic reviews is essential for clinicians and researchers when creating or updating reviews and for decision-making in health care. This study aimed to develop a search filter for retrieving systematic reviews that improves upon the performance of the PubMed systematic review search filter.Methods:Search terms were identified from abstracts of reviews published in Cochrane Database of Systematic Reviews and the titles of articles indexed as systematic reviews in PubMed. Both the precision of the candidate terms and the number of systematic reviews retrieved from PubMed were evaluated after excluding the subset of articles retrieved by the PubMed systematic review filter. Terms that achieved a precision greater than 70% and relevant publication types indexed with MeSH terms were included in the filter search strategy.Results:The search strategy used in our filter added specific terms not included in PubMed''s systematic review filter and achieved a 61.3% increase in the number of retrieved articles that are potential systematic reviews. Moreover, it achieved an average precision that is likely greater than 80%.Conclusions:The developed search filter will enable users to identify more systematic reviews from PubMed than the PubMed systematic review filter with high precision.     

Developing efficient search strategies to identify reports of adverse effects in MEDLINE and EMBASE

OBJECTIVE: This study aimed to assess the performance, in terms of sensitivity and precision, of different approaches to searching MEDLINE and EMBASE to identify studies of adverse effects. METHODS: Five approaches to searching for adverse effects evidence were identified: approach 1, using specified adverse effects; approach 2, using subheadings/qualifiers; approach 3, using text words; approach 4, using indexing terms; approach 5, searching for specific study designs. The sensitivity and precision of these five approaches, and combinations of these approaches, were compared in a case study using a systematic review of the adverse effects of seven anti-epileptic drugs. RESULTS: The most sensitive search strategy in MEDLINE (97.0%) required a combination of terms for specified adverse effects, floating subheadings, and text words for 'adverse effects'. In EMBASE, a combination of terms for specified adverse effects and text words for 'adverse effects' provided the most sensitive search strategy (98.6%). Both these search strategies yielded low precision (2.8%). CONCLUSIONS: A highly sensitive search in either database requires a combination of approaches, and has low precision. This suggests that better reporting and indexing of adverse effects is required and that an effective generic search filter may not yet be feasible.     

Designing a search strategy to identify and retrieve articles onevidence-based health care using MEDLINE

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.     

The performance of adverse effects search filters in MEDLINE and EMBASE

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.     

The effect of CD-ROM MEDLINE on online end-user and mediated searching: a follow-up study

Indiana University School of Medicine Library (IUSML) has traditionally been a high volume searching institution. The dramatic effect of CD-ROM on online end-user searching and the negligible effect on mediated searching was reported in an earlier study. This follow-up study reveals that the proportion of mediated searching has been drastically reduced from 94% in 1986/87 to 39% as of November 1989. Mediated searches are declining in absolute numbers as well. End-user searching, by contrast, has increased by 54% percent over the previous year. A related trend is the increased use of CD-ROM by the librarian as an alternative to mediated online searching. These trends are expected to continue as IUSML expands its CD-ROM operation to include other databases. As mediated searching declines, the librarian's role will increasingly include end-user training.     

Comparing the self-described searching knowledge of first-year medical and dental students before and after a MEDLINE class

Do students need MEDLINE instruction? Do self-described knowledge and search skills match actual ability? To address these questions, librarians developed an assessment tool, a self-administered pre-test/post-test of eighteen skills and concepts taught in the MEDLINE class. By their own assessment, 70% or more of the medical and dental students learned something about each concept taught during the workshop. The study convinced faculty and students that the MEDLINE class is necessary. Librarians and associated faculty agree that the class is important and should continue to be mandatory.     

Updated generic search filters for finding studies of adverse drug effects in Ovid medline and Embase may retrieve up to 90% of relevant studies

Background

The most current objectively derived search filters for adverse drug effects are 15 years old and other strategies have not been developed and tested empirically.

Objective

To develop and validate search filters to retrieve evidence on adverse drug effects from Ovid medline and Ovid Embase.

Methods

We identified systematic reviews of adverse drug effects in Epistemonikos. From these reviews, we collated their included studies which we then randomly divided into three tests and one validation set of records. We constructed a search strategy to maximise relative recall using word frequency analysis with test set one. This search strategy was then refined using test sets two and three and validated on the final set of records.

Results

Of 107 systematic reviews which met our inclusion criteria, 1948 unique included studies were available from medline and 1980 from Embase. Generic adverse drug effects searches in medline and Embase achieved 90% and 89% relative recall, respectively. When specific adverse effects terms were added recall was improved.

Conclusion

We have derived and validated search filters that retrieve around 90% of records with adverse drug effects data in medline and Embase. The addition of specific adverse effects terms is required to achieve higher recall.