Technical Notes - e1 NLM Classification, 5th Edition Additions and Changes List 4 - e2 PubMed: Searching Using Subsets - e3 OLDMEDLINE Database Moves Back in Time - e4 MEDLINEplus - e6 |
OLDMEDLINE Database Moves Back in TimeOLDMEDLINE was first made available in December 1996 with over 307,000 citations originally published in the 1964 and 1965 Cumulated Index Medicus (CIM) (see NLM Technical Bulletin, 1996 Nov-Dec; (293): 1, 4-6). Prior to December 1996, pre-1966 data was not searchable electronically. The OLDMEDLINE database was created in response to user requests and will continue to expand to meet the demand for electronic access to information from these earlier years. In completion of the next phase of NLM's goal to provide online access to citations published in Index Medicus before 1966, over 400,000 citations published in the 1960 through 1963 CIM were added to OLDMEDLINE in November 1998. The file now contains 771,287 citations. OLDMEDLINE is available free to searchers on the Web via Internet Grateful Med (http://igm.nlm.nih.gov) [This link was removed because it is no longer valid.] as well as to ELHILL command language searchers at regular billed rates. To access OLDMEDLINE via ELHILL, enter the command: FILE OLDMEDLINE, or FILE OLDMED, at any USER: prompt. The focus of this article, however, is on using Internet Grateful Med (IGM) to search OLDMEDLINE at no cost.
Introduction
Document Delivery
Note to participating DOCLINE libraries: OLDMEDLINE citations for the years 1964-1965 will route on the SERLINE routing table. Citations for the years 1960-1963 will route on the monograph routing table.
Data Quality
Citations in OLDMEDLINE lack the individual and accumulated changes and improvements that have been made to data in other ELHILL files during annual file maintenance. Certain fields may contain outdated or erroneous data. For example, the multiple parts of a compound surname in the AUTHOR field may appear as one name, e.g.,
All alphabetic characters in citations from the 1964 and 1965 CIM appear in upper case in all fields. For citations from the 1960 through 1963 CIM, only the authors are shown all in upper case. The other information is displayed using both upper and lower case characters. More information about the formats for the Title (TI) and the Keyword (KW) fields is given below.
Date of Publication
Title (TI)
Transliterated/Vernacular Title (TT)
Year (YR)
Figure 1 - Selecting a Year Limit in OLDMEDLINE in IGM
Abstracts
Subject Retrieval: Keywords (KW) and Text Words (TW)
To distinguish these older MeSH Headings from current MeSH in other ELHILL files, all MeSH terms have been placed in the Keyword (KW) field. There are no data in the MeSH Heading (MH) field. As a result, the MeSH terms in OLDMEDLINE do not relate to current MeSH Tree numbers, and the NLM ELHILL "explode" and "pre-explode" capabilities are not functional for this file. The NLM plans to map old MeSH Headings and MeSH Headings/subheading combinations now in the Keyword (KW) field to current MeSH in the future. When you search by subject, IGM automatically looks for your single-word term or multi-word term in both the Keyword field and as single words in the Text Word field. A multiple word MeSH term is searched by ANDING together the individual words as Text Words, as well as looking for the term/phrase in the Keyword field. For example, if you enter the term "diabetes mellitus" on the IGM subject line, as shown in Figure 2 and run your search and then click on the Details of Search button, you will see the terms that are actually searched as displayed in Figure 3. Figure 2 - Searching a Multi-word MeSH Heading in OLDMEDLINE in IGMFigure 3 - Details of Search Display for Diabetes MellitusTwo sample citations from the search on diabetes mellitus are shown in Figures 4 and 5. These citations were chosen to illustrate the differences that will display in the records in this file. Both citations shown are not in English, but only the citation in Figure 4 (1965) shows a vernacular title because only citations from 1964 and 1965 have the Transliterated /Vernacular (TT) field. Only the citation in Figure 5 (1962) displays subheadings because only citations from 1960-1962 contained subheadings in the record. Figure 4 - 1965 OLDMEDLINE CitationFigure 5 - 1962 OLDMEDLINE CitationOnly the MeSH Heading (MH) portion of the MH/sh combination is searchable in the Keyword field. If you enter "diabetes mellitus etiology" on an IGM subject line, the IGM search engine will look for all three words together as a single Keyword and for each of them individually as Text Words ANDed together. Because the complete MeSH heading/subheading combination is NOT present in the Keyword field (only the MH has been put into the searchable Keyword field) your search will retrieve only on diabetes (TW) AND mellitus (TW) AND etiology (TW). Remember, a Text Word search in OLDMEDLINE retrieves words from only the Title and Keyword fields (there are no abstracts in this database). So a search on "diabetes mellitus etiology" will retrieve 23 citations but it will NOT retrieve the citation shown in Figure 6 because this citation contains the word etiology only in the subheading field, not in the Title or Keyword field. For this reason, and because subheadings are not on all citations, searching specifically for subheadings is not recommended in OLDMEDLINE. You may search on words that appear in subheadings in your search, just be aware that your retrieval will be based on these words appearing in the Title or MeSH Heading portion of the MH/sh displayed in the Keyword field. Figure 6 - Citation NOT Retrieved with Search on: diabetes mellitus etiology
Additional Search Tips
When searching, keep in mind the absence of abstracts in OLDMEDLINE, and the fact that fewer MeSH Headings were assigned per article (approximately 6 per citation). Both of these conditions affect subject retrieval. None of the terms assigned to OLDMEDLINE citations are flagged as the major topic of the article. If you try to restrict your search to major topic, you'll get no retrieval. However, because fewer MeSH Headings were assigned, they are each more likely to indicate a major concept in the article. You may truncate a search term by using a colon, e.g., diabet: will retrieve citations with diabetes or diabetic in the Keyword and Title fields. Important to remember: There are no MeSH heading check tags such as HUMAN or ANIMAL present in this database. So don't use check tags in your search strategy, because they are not likely to help you get relevant retrieval.
Updating Frequency and File Maintenance
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