The OLDMEDLINE subset in PubMed® represents journal article citations from two print indexes: Cumulated Index Medicus (CIM) and the Current List of Medical Literature (CLML). Created by the National Library of Medicine® (NLM®), there are approximately 2,000,000 article citations from international biomedical journals that cover the fields of medicine, preclinical sciences and allied health sciences from 1946 through 1965. OLDMEDLINE records, most of which are included in the MEDLINE® database, can be searched via PubMed.
In 1964, NLM began using the computerized MEDLARS® (Medical Literature Analysis and Retrieval System) as a mechanism for producing Index Medicus®. In 1971, MEDLARS went online with the introduction of MEDLINE, an interactive searchable database of data from the 1966 Index Medicus forward. The 1964 and 1965 issues of Index Medicus, while available in electronic form, were not included in MEDLINE because of format differences. In the mid-1990s, NLM was assisted in its effort to provide online access to these older citations by the Deutsches Institut fur Medizinische Dokumentation und Information (DIMDI), the International MEDLARS Center in Germany. DIMDI had tapes of the original data from the 1964 and 1965 Cumulative Index Medicus, which they converted and then supplied to NLM to create OLDMEDLINE in 1996. The citations from the 1960 - 1963 CIM and the 1946 - 1959 Current List of Medical Literature (CLML) were converted from print copy into machine-readable form.
|Date Added||Citations Added||From Print Index|
|1962 - 1963 CIM
1960 - 1961 CIM
|May 2002||103,427||1957 CLML|
|September 2004||55,850||53,533 citations from 1950 CLML
2,317 citations from 1951 - 1965*
|December 2007||55,557||1949 CLML|
|February 2008||2,332||1949 CLML additional citations*|
|October 2008||70,046||1948 CLML|
|March 2010||63,839||1947 CLML|
|November 2010||49,428||1946 CLML|
*In order to load OLDMEDLINE data into PubMed, each citation must be linked to a parent serial record in LocatorPlus®. Determining the proper link for some of these older citations takes research time which can result in the citations being made available later than the online debut date for the majority of a year's index. Research and user reports also uncover gap issues that NLM adds and citations that are duplicates that NLM deletes; these changes are not reflected in the counts given in the chart.
NLM expects to continue converting citations from its older print medical indexes to machine-readable form and to add these citations to the PubMed OLDMEDLINE citation subset as time and resources permit.
OLDMEDLINE records have been created using standards that are different from the data entry standards for MEDLINE records. There are also variations among OLDMEDLINE citations in the data elements (fields) present in the citation as well as in their format, depending on the original source from which the citations were obtained. For details, see the individual MEDLINE/PubMed Data Element (Field) Descriptions.
OLDMEDLINE citations lack the individual and accumulated changes and improvements that have been made to data in other NLM files during annual file maintenance. Certain fields may contain outdated or erroneous data and the data are not cosmetically consistent from year to year (e.g., the use of upper/lower case). The citations basically reflect the contents of the original print indexes that were produced under policy and procedures of the time. The exceptions to this are that NLM has identified and updated the Journal Title Abbreviation and added the current ISSN. Each OLDMEDLINE citation is linked to a parent serial record in the NLM online catalog, LocatorPlus. In addition, beginning with 2005 Year-End Processing, OLDMEDLINE citations with Medical Subject Headings (MeSH®) (see MeSH Mapping Project) are included in the individual and accumulated changes and improvements that are made to the NLM data during annual maintenance, notably changes to the MeSH vocabulary.
Note the following aspects of OLDMEDLINE subset citations when searching:
Lack of Abstracts
When searching OLDMEDLINE citations, it is important to remember that the absence of abstracts affects subject retrieval.
Journal Article Title
Approximately 106,000 citations in a foreign language don't have an article title in English which affects subject retrieval.
Original Subject Headings
To distinguish the original subject headings from the print indexes from current MeSH, all original subject headings have been placed in the Other Term [OT] field of OLDMEDLINE subset records in PubMed. Note the following characteristics of these subject headings:
- Few subject headings (approximately 3 - 5 per citation). See the Sample Record One (MEDLINE Display) below. The 1964 and 1965 citations tend to have more subject headings (approximately 3 - 8 per citation). See the Sample Record Two (MEDLINE Display) below.
- "Check tag" headings (e.g., ANIMALS, CHILD, INFANT) were applied inconsistently and should not be used to search.
- Original subject headings have not been updated and may not match current MeSH vocabulary.
- Subheading practice varied:
- No subheadings on 1963 - 1965 CIM citations and 1950 - 1951 CLML citations.
- Various subheadings on 1960 - 1962 CIM citations, 1946 - 1949 CLML citations, and 1952 - 1959 CLML citations.
- All original headings designated as major topic (the exceptions are explained under the MeSH Mapping Project section below).
Because these original subject headings are not current MeSH, the subject headings in the [OT] field of OLDMEDLINE subset citations do not relate to current hierarchical MeSH Tree numbers, and the MeSH search capabilities (i.e., "explosions") that collect indented (more specific) terms are not functional for these data in the OT field.
NLM has begun an OLDMEDLINE OT subject heading-to-MeSH heading mapping project. This project maps the original subject headings assigned to the citations when they appeared in the print indexes to the current MeSH vocabulary. NLM estimates that as of December 2012 approximately 93% of the OLDMEDLINE citations have at least one current MeSH heading (while 81% have been completely mapped) and will, therefore, be retrieved by PubMed searches that incorporate MeSH Headings. About 80% of the original main subject headings have been mapped (this has dropped from 89% as more new headings are encountered with each new index that is converted; also, many of the subheadings attached to the original subject headings remain to be mapped). The original subject headings are being retained in the OT field.
Please note: The majority of current MeSH headings added to OLDMEDLINE subset records have been added as Major MeSH Headings because sixteen of the eighteen years of data have only headings under which the citations appeared in the print indexes. However, two years of data, the 1964 and 1965 CIM, contain additional MeSH headings that do not represent the major point of the article yet are also set to Major status because the original distinction between major and not major had been lost over the years during various conversion efforts and NLM did not have the resources to restore that distinction. Remember, as explained above, that OLDMEDLINE citations have MeSH headings such as the commonly used check tags for Animals, Age groups, etc. applied inconsistently and that subheading practices varied greatly over the years. An asterisk denotes major topic, i.e., MH - *Autopsy. Geographic headings and most check tags do not have an asterisk.
The date of introduction of a MeSH heading is not a factor for the mapping of OLDMEDLINE citations. For example, ROENTGEN RAYS is mapped to X-RAYS which wasn't added to MeSH until 1975. For searching, this means there is a likely a PubMed retrieval gap on the heading X-RAYS for the approximate timeframe 1966 - 1974 which should be addressed by alternate search techniques such as text words or related MeSH.
During Year-End Processing, non-major MeSH headings are added to citations. The MeSH headings added are associated with Supplementary Concept Records (SCRs). Each SCR has an associated Main Heading(s), which is its Heading Mapped-to (HM) in the MeSH Browser. For example, when the RN - 7778-18-9 (Calcium Sulfate) is added to an OLDMEDLINE citation, then the MH - Calcium Sulfate is added as well.
As of late 2006, citations from the OLDMEDLINE print index sources that have had all of their original subject headings mapped to current MeSH carry the status tag [PubMed - indexed for MEDLINE]. See Sample Record Two (Summary Display) below. A search for medline [sb] in PubMed will include these records. Citations that have not had all of their original subject headings mapped to current MeSH will have the status tag [PubMed - OLDMEDLINE]. See Sample Record One (Summary Display) below. A search for oldmedline [sb] will identify these records. Citations digitized in the future from earlier years of the print index CLML will be entered in PubMed with the citation status of [PubMed - OLDMEDLINE] until their original subject headings are completely mapped to current MeSH. Once this mapping is completed, these records will be designated as MEDLINE records and their citation status will become [PubMed - indexed for MEDLINE].
To search for all citations that originated from the OLDMEDLINE print index sources, regardless of their status, search jsubsetom in PubMed.
It is important to note that there are also tens of thousands of citations in PubMed that pre-date 1965 as a publication date with the status of [PubMed] as a result of the NLM Back Issue Digitization Project and not from the old print indexes. There are no Other Terms or MeSH Headings on these citations.
See these NLM Technical Bulletin articles for additional information:
OLDMEDLINE subset records are included in PubMed and available free of charge.
All articles cited in PubMed, including those in the OLDMEDLINE subset, can be ordered using Loansome Doc®.
Sample Record One: PubMed Summary display format for a 1955 OLDMEDLINE citation
- [Malignant lymphogranuloma of the cecum.]
Minerva Med. 1955 Dec 26;46(103):1987-91. Italian. No abstract available.
PMID: 13288161 [PubMed - OLDMEDLINE]
Sample Record One: PubMed MEDLINE display format for a 1955 OLDMEDLINE citation
- PMID - 13288161
OWN - NLM
STAT - OLDMEDLINE
DA - 19561201
DCOM - 20030501
LR - 20051116
IS - 0026-4806 (Print)
IS - 0026-4806 (Linking)
VI - 46
IP - 103
DP - 1955 Dec 26
TI - [Malignant lymphogranuloma of the cecum.]
PG - 1987-91
FAU - CALZOLARI, G
AU - CALZOLARI G
LA - ita
PT - Journal Article
TT - Linfogranuloma maligno del cieco.
PL - Not Available
TA - Minerva Med
JT - Minerva medica
JID - 0400732
SB - OM
MH - *Hodgkin Disease
OID - CLML: 5629:40397
OTO - NLM
OT - *CECUM/diseases
OT - *HODGKIN'S DISEASE
EDAT - 1955/12/26
MHDA - 1955/12/26 00:01
CRDT - 1955/12/26 00:00
PST - ppublish
SO - Minerva Med. 1955 Dec 26;46(103):1987-91.
Sample Record Two: PubMed Summary display format for a 1965 MEDLINE citation that originated from OLDMEDLINE
- POSTMORTEM VITREOUS GLUCOSE DETERMINATIONS.
STURNER WQ, GANTNER GE Jr.
J Forensic Sci. 1964 Oct;9(4):485-91. No abstract available.
PMID: 14226373 [PubMed - indexed for MEDLINE]
Sample Record Two: PubMed MEDLINE display format for a 1965 MEDLINE citation that originated from OLDMEDLINE
- PMID- 14226373
OWN - NLM
DA - 19650301
LR - 20111117
IS - 0022-1198 (Print)
IS - 0022-1198 (Linking)
VI - 9
IP - 4
DP - 1964 Oct
TI - POSTMORTEM VITREOUS GLUCOSE DETERMINATIONS.
PG - 485-91
FAU - STURNER, W Q
AU - STURNER WQ
FAU - GANTNER, G E Jr
AU - GANTNER GE Jr
LA - eng
PT - Journal Article
PL - UNITED STATES
TA - J Forensic Sci
JT - Journal of forensic sciences.
JID - 0375370
RN - 0 (Blood Glucose)
RN - 50-99-7 (Glucose)
SB - OM
MH - *Autopsy
MH - *Blood Glucose
MH - *Clinical Laboratory Techniques
MH - *Diabetes Mellitus
MH - *Forensic Medicine
MH - *Glucose
MH - *Pathology
MH - *Vitreous Body
OTO - NLM
OT - *AUTOPSY
OT - *BLOOD SUGAR
OT - *DIABETES MELLITUS
OT - *DIAGNOSIS, LABORATORY
OT - *FORENSIC MEDICINE
OT - *GLUCOSE
OT - *PATHOLOGY
OT - *VITREOUS BODY
MHDA- 1964/10/01 00:01
PST - ppublish
SO - J Forensic Sci 1964 Oct;9(4):485-91.
For information about OLDMEDLINE data or other NLM services, contact:
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