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Global Index Medicus Help Guide

Database with international coverage of Health Sciences topics.

Accessibility Note

Items you need to type, click, or press will be displayed in computer code style.

  • If you have the option to adjust your screen reader's settings to notify you when there is an HTML tag for "code", that will help to alert you to these items. This is not a typical setting for screen readers, so we have written the guide to clearly signal when text is meant to be clicked or typed (e.g., most example searches are preceded by the term "Example:");
  • Searches must be entered exactly as they appear, including all punctuation like quotes and parentheses.
    • Because of this, screen reader users should enable their readers to pronounce punctuation while using this guide and when writing search strings for GIM. Strings can be composed in a text document with punctuation on then run in GIM with punctuation off.
  • Boolean operators (like AND, OR, and AND NOT) should be typed in all capitals to ensure the database recognizes them as operators. 

Need Help?

How do I improve search results? A quick checklist

No References or Too Few References

  • Check for:
    • Misspellings in your search string.
    • Missing quotes or parentheses in your search string. Medsyntax can help you check.
    • Misplaced parentheses that change how your concepts are grouped.
  • Include:
    • Plurals
    • Different verb forms
    • British spellings of terms (hemorrhage/haemorrhage)
  • Consider: 
    • Adding a truncation symbol at the end of a term to pick up variant endings: program* retrieves programs, programming, programme, etc.
    • Using a mix of keywords and DeCS/MeSH subject descriptor terms.
    • Decreasing the number of concepts joined by AND.
    • Increasing the number of synonyms or alternatives joined by OR.
  • More strategies to broaden your search

Too Many References

  • Check for:
    • All quotes must be straight (simple) quotes. Example: "anti depressants" not “anti depressants”
  • Consider:
    • Increasing the number of search concepts that are ANDed together.
    • Using fewer synonyms for terms.
    • Removing acronyms that can stand for multiple things.
    • Adding a filter to limit your search to type of article, language, age group, current years, etc.
    • Using the Advanced Search or Main Subject filter to make a DeCS/MeSH term the main focus of the article.
    • Searching for significant words in the TITLE of the article by using field tags.
  • More strategies to narrow your search

Still getting unsatisfactory results? Ask a librarian!

Broaden Your Search to Find More Citations

1. Identify more Search Terms

  • Select a relevant article and click the title to see the full record for the article. Inspect the author keywords and (if present) Subject fields at the end of the abstract before the Similar section. Click on an individual term to run a search on it, or copy it to check it out in the Subject descriptor lookup. Author keywords in GIM often match the DeCS/MeSH terms. 
  • Check the list of synonyms for your DeCS/MeSH terms. Add these using OR in the tw, title, abstract, keyword field. Remember to use straight (simple) quotes around any phrases! Example: mh:(C04.557.470.200.025*) OR tw:(adenocarcinoma* OR "malignant adenomas" OR "malignant adenoma" OR "granular cell carcinomas" OR "granular cell carcinoma" OR "tubular carcinomas" OR "tubular carcinoma" OR "cribriform carcinomas" OR "cribriform carcinoma")
    example of synonyms column in DeCS thesaurus in Global Index Medicus

2. "Explode" the DeCS/MeSH term to include narrower terms

Searching on the name of the DeCS/MeSH term does not search on its narrower terms. Including those narrower terms, which is often called exploding the term, requires using the category number of Descriptor followed by *. The asterisk for explode does NOT work with text descriptor and it may make the website hang if you try.

  • mh:"Lung Diseases, Fungal" - 441 results
  • mh:C01.748.435 - 441 results
  • mh:C01.748.435* - 1,002 results

3. Replace terms that are too general/too specific.

In a search, the general term for a category does not always return results for items belonging to that category. For example, a search on tw:"substance use disorders" will only return results that use exactly that phrase or the unexploded DeCS/MeSH term "Substance Use Disorders." To broaden the search, you could add specific types of substance use disorders using OR, along with their synonyms.

  • tw:("substance use disorders") - 5,802 results
  • tw:("substance use disorders" OR "Narcotic-Related Disorders") - 5.808 results
  • tw:("substance use disorders" OR "Narcotic-Related Disorders" OR "Opioid-Related Disorders") - 5,977 results
  • tw:("substance use disorders" OR "Narcotic-Related Disorders" OR "Opioid-Related Disorders" OR "Morphine Dependence") - 6,162 results

4. Find Similar Results

Select a citation of interest and click the title to see the full record for the article. A selection of similar results will be listed below the abstract. Click the down arrow or sideways arrows to view more.

Reduce Your Search Results

1. Review your research question

Are all the core concepts in your research question represented in your search string or by a filter? If not, add that concept with AND.

2. Limit results using Filters

Note: Filters are based on the DeCS/MeSH terms assigned to an article. There may be articles relevant to your topic where the corresponding DeCS/MeSH term was not assigned. Because of this, searches narrowed by using filters may not be comprehensive.

Limit by Main Subject

Select one or more items from the Main Subjects filter to restrict to articles where that item is the core topic of the article, then click the filter button. Example: for the mh:"Lung Diseases, Fungal" search above could be limited by selecting the Main Subject of "Immunocompromised Host". If more than one Main Subject is selected, they will get searched with OR between them. Example: if both "Immunocompromised Host""Male" are selected, GIM will search that as "Immunocompromised Host" OR "Male". The Main Subject options are based on the DeCS/MeSH terms assigned to the articles retrieved by the search.

Limit by Type of Study

Consider what kinds of research could find an answer to your question. Select one or more applicable study methodologies from the Type of Study filter. These will be searched with OR between them. Example: type_of_study:("guideline" OR "systematic_reviews").

Limit by Region

Country/Region as subject can be added to the filter options from under the Add filters button at the top of the sidebar. The options will vary based on the search results. If more than one Country/Region is selected, they will get searched with OR between them: (pais_assunto:("brasil" OR "bolivia" OR "peru")).

Note: This filter primarily works with countries in Latin America.  To search other regions or more comprehensively, it can be combined using OR with keywords or DeCS/MeSH terms specific to the region: ((tw:"sub-saharan") OR ( pais_assunto:("africa")))

Once selected, filters remain in place until you change or remove them.

3.  Replace or adjust terms that generate irrelevant results

  • Sometimes a word will mean different things in different contexts. If you are getting a lot of irrelevant results that are similar, is there a term they have in common? If so, check for a DeCS/MeSH term that matches the meaning you want, and use that instead.
  • Already using a DeCS/MeSH term? Check the DECS thesaurus to make sure that you are using the most specific one that is appropriate to your question. Is there an appropriate subheading that would narrow it to better match your question?

Filter Results

Learn more about managing results, like using the filters on the search results page! 

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