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Searching the Literature: A Guide to Comprehensive Searching in the Health Sciences

Students and researchers in the health sciences are often required to conduct comprehensive searches of the literature. Follow the steps in this guide to learn how this process works.

Textwords vs Subject Headings

For a comprehensive search, always search both subject headings and textwords for each concept.

 

Textword searching means using terms you choose yourself to search the "record" of a database. The record DOES NOT include the full-text article. It mainly includes the TITLE, ABSTRACT, and AUTHOR-PROVIDED KEYWORDS. Textwords are often referred to as keywords.

Subject heading searching means using preassigned terms to search for articles labelled with that term. Each database uses its own subject headings - MEDLINE's are called MeSH.

EXAMPLE:

Sometimes subject headings and textwords are the same, but often they aren't. The MeSH heading in MEDLINE for support groups is Self-Help Groups. Using only the textword "support groups" will leave out some articles tagged with the subject heading, but using only the subject heading will leave out some articles that use the textword.

Why use Subject Headings (aka a Controlled Vocabulary)?

Subject Databases use "controlled vocabularies" made up of subject headings, organized hierarchically. Subject headings solve 2 major problems we encounter when relying solely on textword searching: Synonyms and Ambiguity. 

Synonyms:

Pet Therapy = animal assisted therapy, therapy dog, therapy dogs, equine-assisted therapy, therapy animals, etc. 

If you only searched for 'pet therapy', you'd miss all articles that use 'therapy dog' to describe that concept. It's very difficult to think of all the potential ways of expressing a concept. 

Ambiguity: 

Pet therapy = animal assisted therapy, Positron emission tomography

If you searched for 'pet therapy', thinking you'd retrieve only articles about therapy animals, you'd have to sift through quite a bit of literature on PET imaging. 

So, to solve these problems, you could search the subject heading for the concept of pet therapy. In Medline, the Mesh is Animal Assisted Therapy. In CINAHL it's Pet Therapy. 

Different Subject Databases use Different Controlled Vocabularies

Search strategies MUST be customized for each database:

  • databases use different subject headings to describe the same concept
  • a database can't be searched effectively unless the correct subject headings are used
  • each database requires it's own, unique search strategy 
Database Controlled Vocabulary
MEDLINE MeSH 
EMBASE EMTREE
CINAHL CINAHL Headings
PsycINFO APA Thesaurus
Sociological Abstracts Thesaurus of Sociological Indexing Terms
AMED AMED Thesaurus

Textwords: Codes and Tips

Textword Syntax Cheat Sheet

 

Truncation

Proximity/Adjacency Operators

Field Codes (a selection)

Parentheses

Truncation symbols can be used to search for endings of words.

Note: Be careful when truncating 3-letter words (because cat* = catastrophe, cataclysmic, catatonic)

 

The proximity operator searches for terms near each other.

Note: Adjacency runs in both directions. Searching for heart ADJ5 attack will search for ‘heart attack’ or ‘attack of the heart’, etc (although the database may not find anything).

 

Tell the database where to look for your textwords.

 

Increase the efficiency of your querying by forcing order of operations. 

OVID Databases
(e.g. Medline, Embase, PsycINFO, AMED)

 

* or $ or  :

famil*= family OR families OR familiar OR familiarity OR familicide, etc

 

 

ADJn

(where ‘n’ stands for n-1. Use a number from 1-99 or left blank)

oil adj1 olive = the two words next to each other, in any order

oil adj3 olive = olive oil, but also “olive and canola oil”

 .ti = title
 .ab = abstract
 .tw = title OR abstract
 .kw = author-provided               keyword exact
 .kf = word in author                  provided keyword
 .pt = publication type
 .mp = multipurpose,                 includes subject               heading

((Oil OR oils) ADJ3 (grape* OR olive OR canola OR sunflower)).tw,kf

EBSCO Databases (e.g. CINAHL)

 

*

NOTE: (*) may also be used

between words to match any word.

 

a midsummer * dream = a midsummer night’s dream

 

 

Nn
(where ‘n’ is a number from 1-99 or left blank)

 

 

 TI = title
 AB = abstract
 TX = all text
 IN = instrumentation
 SO = publication name

TI ( (oil OR oils) N3 (grape* OR olive OR canola OR sunflower) ) OR AB ( (oil OR oils) N3 (grape* OR olive OR canola OR sunflower) )

ProQuest (e.g. Sociological Abstracts, ASSIA)

 

 

*
 

NOTE: (*) can ALSO be used at the
beginning (left-hand truncation),
the end (right-hand truncation),
or in the middle of a word.

*old = told, household, bold,

TIP: Do NOT truncate words with <3 letters. 

NEAR/#
(note: must specify a number, cannot leave blank)

 TI = title

 AB = abstract

 NOFT = everything except   full-text

NOFT((oil) NEAR/3 (grape* OR olive OR canola OR sunflower))

Example Textwords (OVID Medline)

Super precise textword search:

  • Treatment goal setting.tw – 9 hits

Balanced textword search:

  • (goal* OR priority) ADJ3 (set* OR plan* OR establish*).tw – 11914 hits

Sensitive textword search:

  • ((goal* or priorit* or target*) ADJ3 (agree* or negotiate* or convers* or discuss* or propos* or develop* or formulat* or elaborate* or establish* or identif* or write or written or state* or specif* or construct* or manag* or direct* or orient* or cent?red or achiev* or evaluat* or attain* or facilitat* or misalign* or align* or care or outcome* or plan* or set* or health or select*)).tw.– 274896 hits

ProQuest Databases - Tips & Tricks for Comprehensive Searching

It is relatively common to encounter errors when searching databases on the ProQuest interface (eg. Sociological Abstracts, ERIC, Phys Ed Index, etc). Troubleshoot your search by following these important tips: 

  1. Make sure you are only searching 1 database at a time. You should see the name of your database at the top of the page. 

     
  2. Search your textwords separately in TI or AB, or use the code NOFT (Anywhere but Full Text). TI,AB((chronic OR traumatic) N/2 brain injur*)) will NOT work.

    For example, in Sociological Abstracts: 

    Option A: TI((chronic OR traumatic) NEAR/2 ("brain injur*")) OR AB((chronic OR traumatic) NEAR/2 ("brain injur*")) = 114 results

    Option B: NOFT((chronic OR traumatic) N/2 ("brain injur*")) = 123 results

    Option A will likely be more precise and potentially less redundant. Option B is quicker to create, but since it includes additional search fields, will be less precise and potentially introduce redundancies into your search strategy. 
     
  3. Do not truncate words <3 letters. Consider using defined truncation (ex. NOFT(disabilit[*3]) but it’s not necessary.
     
  4. Avoid using the Combine Searches function (eg. S1 and S2) to combine your search sets. For long queries, it can cause time-outs. Combine sets in the Command Line or Advanced Search instead. Ensure correct use of parentheses. 


     
  5. If you are still encountering errors in ProQuest for your systematic or scoping review search, contact ask.gerstein@utoronto.ca.