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Ovid MEDLINE Subject Limits Overview

Ovid MEDLINE includes limits based on PubMed's subject subsets. Subject searches executed with these Subject Limits retrieve a specific subset of citations within Ovid MEDLINE.

AIDS
Bioethics
Cancer
Complementary Medicine
History of Medicine
Space Life Sciences
Systematic Reviews
Toxicology

Unqualified Searches in PubMed and Their Equivalencies in Ovid

Ovid has duplicated the PubMed subject subset searches as closely as possible. Unqualified searches are executed differently in Ovid and PubMed. In PubMed, unqualified searches will be searched in one of a few ways.

As MeSH and text words; when PubMed searches an unqualified term in this manner, it automatically explodes the MeSH and subheadings.
For example, a search in PubMed for the term Materia Medica translates to the Ovid search (Materia Medica.tw,sh,hw,rw,pn,kf,sm,ms. OR exp Materia Medica/).
Note that the Text Word (TW) field in Ovid includes only title and abstract information; therefore, to match the PubMed definition of a Text Word search, Ovid searches the Text Word, MeSH Subject Heading, Subject Heading Word, Name of Substance, Personal Name as Subject, Keyword Heading Word, Space Flight Mission, and Molecular Sequence (tw,sh,hw,rw,pn,kf,sm,ms) fields.
As a journal abbreviation or journal name.
For example, in PubMed, the search aids clin rev retrieves all records available in the journal AIDS Clinical Review, while in Ovid, it is recommended to search for the journal's ISSN, 1045-2877.is.
As an author; when PubMed searches an unqualified term in this manner, it automatically truncates the author terms.
For example, the PubMed search berthoz a translates to berthoz a$.au. in Ovid.
As all fields, or in name of substance.
An Ovid search strategy that utilizes the All Searchable Fields (AF) or Name of Substance (RW) fields will match this PubMed strategy.

Differences Between Retrieval in PubMed and Ovid

There are differences in the number of records retrieved between the Ovid and PubMed subject subset searches. The following are the primary reasons why the number of records retrieved may differ.

PubMed includes more records from old MEDLINE, in process, and publisher supplied sets of data
PubMed updates records before Ovid receives them
PubMed updates subject headings before Ovid receives them
PubMed truncation has a limit of 600 variations, while Ovid has no limit
PubMed searches Pharmacologic Action Terms as a field, while Ovid does not have a separate field for Pharmacologic Action Terms
Ovid retrieves more records if there is non-MeSH branching in a tree because PubMed does not include records within non-MeSH branches

This table shows examples of PubMed search strategies, along with the PubMed and Ovid syntax to retrieve the same results for each strategy.

PubMed Search Strategy	PubMed Translation (what it executes)	Ovid Equivalent Search
berthoz a	berthoz a[Author]	berthoz a$.au.
jsubsetq	jsubsetq [All Fields]	q.sb
Historical article [pt]	historical article [pt]	Historical article.pt.
Bone cements/ae	bone cements/adverse effects [MeSH Terms]	Exp bone cements/ae,po,to
Plants, toxic [mh]	"plants, toxic" [MeSH Terms]	Exp plants, toxic
nutriceutical*	(((nutriceutical [All Fields] OR nutriceutical' [All Fields]) OR nutriceuticals [All Fields]) OR nutriceuticals' [All Fields])	nutriceutical$.af.
bioelectromagnetic* [tw]	(bioelectromagnetic [tw] OR bioelectromagnetics [tw])	bioelectromagnetic$.tw,sh,hw,rw,pn,kf,sm,ms.
Materia medica	("materia medica" [MeSH Terms] OR materia medica [Text Word])	Materia medica.tw,sh,hw,rw,pn,kf,sm,ms. OR exp Materia medica/
Acupunct Electrother Res	"Acupunct Electrother Res" [Journal]	0360-1293.is.
"uncaria tomentosa"	"uncaria tomentosa" [All Fields]	uncaria tomentosa.af.
Manner hw[ps]	manner hw [ps]	Manner hw.pn.
Fasting[majr]	"Fasting" [MeSH Major Topic]	Exp *fasting/
Magnetics/tu[mh:noexp]	magnetics/therapeutic use [MeSH Terms:noexp]	Magnetics/tu
"medium chain" triglycerides	("medium chain" [All Fields] AND ("triglycerides" [MeSH Terms] OR triglycerides [Text Word]))	"medium chain".af. AND (exp triglycerides/ OR triglycerides.tw,sh,hw,rw,pn,kf,sm,ms.)
therapy	(("therapy" [MeSH Subheading] OR "therapeutics" [MeSH Terms]) OR therapy [Text Word])	th.fs. or dh.fs. or dt.fs. or nu.fs. or pc.fs. or rt.fs. or rh.fs. or su.fs. or tr.fs. or exp therapeutics/ or therapy.tw,sh,hw,rw,pn,kf,sm,ms.
diseases category[mh]	diseases category[mh]	exp "bacterial infections and mycoses"/ or exp virus diseases/ or exp parasitic diseases/ or exp neoplasms/ or exp musculoskeletal diseases/ or exp digestive system diseases/ or exp stomatognathic diseases/ or exp respiratory tract diseases / or exp otorhinolaryngologic diseases/ or exp nervous system diseases/ or exp eye diseases/ or exp "urologic and male genital diseases"/ or exp "female genital diseases and pregnancy complications"/ or exp cardiovascular diseases/ or exp " hemic and lymphatic diseases"/ or exp "congenital, hereditary, and neonatal diseases and abnormalities"/ or exp "skin and connective tissue diseases"/ or exp "nutritional and metabolic diseases"/ or exp endocrine diseases/ or exp immunologic diseases/ or exp disorders of environmental origin/ or exp animal diseases/ or exp "pathological conditions, signs and symptoms"/

For more information, please see: http://www.nlm.nih.gov/bsd/pubmed_subsets.html. If you have any questions or concerns please contact your Ovid Support Representative at support@ovid.com.