Global Index Medicus Help Guide

• It is helpful to have a general research topic in mind before searching a database for literature.
  • Most databases are difficult to browse without a topic to start with.
• You may develop your topic further as you search. 
  • This does not apply to Systematic Reviews, which should follow a protocol and requires librarian involvement. 
• Check for any instructions from your syllabus or course assignment if applicable. 

If your topic is not related to global health or the countries covered by Global Index Medicus (GIM), consider searching in a database more relevant for your topic. Here are some alternatives to explore: 

• Health Sciences Toolkits, most of the toolkits provide a list of databases based on the topic of the toolkit you've opened. 
• Select health sciences databases: 
  • PubMed (PubMed Guide) 
    Contains biomedical literature from around the world. 
  • Embase (Embase Guide)
    Contains biomedical literature from around the world with special emphasis on medical devices and pharmaceuticals. 
  • Web of Science (Web of Science Guide)
    Contains biomedical and social sciences literature from around the world. 
  • CINAHL Complete (CINAHL Complete Guide) 
    Contains biomedical nursing literature from around the world, often focused on the patient perspective. 
• Database Guides from the Health Sciences Library 
• Incomplete alphabetical list of health sciences databases 

• Identify various concepts in your topic. 
  • You may find structuring your topic into a PICO (Patient, Intervention, Comparison, Outcome) or similar format may be helpful; the HSL's Writer's Guide to Research Questions elaborates on structured research questions. 
• For illustrative purposes, our example topic will be "contraceptive use in Africa". This topic can be broken into two or three concepts:
  • As two concepts: contraceptive use AND Africa 
  • As three concepts: contraceptive AND use AND Africa 
  • The difference between using two or three concepts in this case depends on what is meant by "use": 
    • If "contraceptive use" only referenced contraceptives in use in Africa, then using two concepts will likely be sufficient.
    • If "contraceptive use" implied information about attitudes and beliefs regarding contraceptives, then using all three concepts is important. 
  • For this example, we will use the simpler interpretation of "contraceptives in use in Africa". 
• You may find it helpful to use a spreadsheet or a table in your word processor to organize your concepts. This is not required; only use a table if it is helpful to you. Alternatives include a list or paragraph for each concept. 

Table of concepts:

• We strongly recommend using a word processor like Microsoft Word or Google Docs or a spreadsheet like Microsoft Excel or Google Sheets. Reasoning: 
  • GIM does not save your search history, so all of your work can be erased by an accidental click if not saved in another location. 
  • Reproducibility: saving your search elsewhere makes it easier to repeat another day or hour. 
    • Helps you avoid repeating work you've done before, even just from forgetting your best search strategy when returning to the topic the next day. 
  • This is important for reporting your search, including to help you explain to another person or journal publication why you made a decision about the topic or search strategy. 

Table of concepts with Keyword row that we'll populate with the strategies described in this step: 

• For each concept, consider other ways of talking about it.
  • Perhaps someone would use specific contraceptive devices or use the term "contraception" instead of "contraceptive".
  • Keep in mind that how you think of a topic may not be the same as how researchers write about the topic. 
  • Also keep in mind that some of these articles will have translated abstracts and the translation may not be grammatically correct. 
  • Be creative! 
  • Having more keywords in your search means you will miss fewer articles. It also means you will have more search results to work with! 

GIM uses DeCS and MeSH terms for controlled vocabulary.

Controlled vocabulary can be viewed as a strict and limited dictionary the database uses to make search results more precise. There is one term for a concept and each article has around five to twenty controlled vocabulary terms assigned to it. The terms are assigned to an article because that is what the article is about; they are not assigned to an article that just mentioned the concept or a homonym. 

You must include these terms exactly as written by the database. 

Table of concepts with Keywords and Controlled Vocabulary terms that we'll populate with the strategies in this step.

There are two ways to browse for MeSH terms (method 1) and one way to browse for DeCS and MeSH terms at the same time (method 2). 

Method 1: MeSH Terms

1. Open the MeSH Browser (does not include DeCS terms) 
2. Search for your first concept. 
3. If there are no results, try a synonym for your concept. 
4. If there are results, click on and view each one. Review the scope note for each term to make sure it means what you think it means. 
   1. Terms in all capitals within the description of a MeSH term are MeSH terms themselves and can be added to your search if they are more appropriate. 
5. Select the term(s) that best fit the meaning of your concepts. 

Method 2: DeCS and MeSH Terms

1. In GIM, click on Search by DeCS/MeSH descriptors (found above the search box on the GIM homepage or search results page).
2. Search for one concept at a time by typing in the concept name you recorded in step 2 or with keywords generated in step 3. Click on a suggested term as GIM auto-fills the end of your search term. 
   1. If you press Enter on your keyboard while typing your concept into the descriptors search box, the page will refresh and clear the box and any results. 
   2. If there are no results as you are typing a concept name, try other synonyms and keywords to find a relevant DeCS or MeSH term.
3. When you find a relevant term, copy the term and its categories (the category starts with a letter followed by a string of numbers with periods) into your separate search document. 
4. Review the Hierarchy to determine if anything listed below AND indented by your selected subject descriptor is relevant to the search. 
   1. In our example topic, we are likely interested in all areas of Africa, so once we've found the DeCS/MeSH term Africa / África / África, we must copy the Category Z01.058 and add an asterisk to the end like so: Z01.058*. The asterisk tells the database that you want to include all narrower concepts in your search. 

While natural language searching (i.e., typing like you talk) works for Google and similar products, most databases are not designed to deal with this as easily. Because of this, we must speak to Global Index Medicus (GIM) in the language it understands, with database-specific syntax. 

Boolean operators are usually AND, OR, and AND NOT (while not required in every database, putting these in all capitals tells many databases that this is an operator and not part of a natural language search). 

• AND is used to connect two concepts.
• OR is used to connect synonyms within a concept.
• AND NOT is used to exclude a term from your search results; it must be used with caution because it can and will remove relevant results that discuss the excluded term(s) and results that also discuss the topic you're interested in. 

Now that you have some understanding of why we're doing this, here is how to connect your terms with Boolean operators and add syntax to instruct the database on how to interpret your search string: 

1. Within one concept, connect all the keyword terms with an OR and put parentheses around the search string. 
   1. Example: (contraceptive OR condom) 
2. Add a field tag to this search string.
   1. Field tags tell the database where it can search for your terms. The default is tw:, which searches articles' title, abstract, subject, and keywords for your terms. 
   2. Example: tw:(contraceptive OR condom)
3. Within the same concept, connect all DeCS/MeSH terms' categories with OR and put parentheses around the search string. 
   1. Example: (D27.505.696.875.360 OR D27.505.954.705.360) 
4. Add the field tag to your DeCS/MeSH terms. The field tag for DeCS and MeSH terms must be mh:.
   1. Example: mh:(D27.505.696.875.360 OR D27.505.954.705.360)
5. Add an OR between these two search strings with field tags and surround with parentheses.
   1. Example: (tw:(contraceptive OR condom) OR mh:(D27.505.696.875.360 OR D27.505.954.705.360))
6. Follow steps 1-5 for each concept. 
7. Combine concepts with an AND between the search strings you created in step 5.5. 
   1. Example: (tw:(contraceptive OR condom) OR mh:(D27.505.696.875.360 OR D27.505.954.705.360)) AND (tw:(africa OR sahara) OR mh:(Z01.058))

Type or paste your search terms into the search box, either on the homepage or search results page of GIM, then click the search icon or press Enter on your keyboard to execute the search. 

Each time you edit your search terms, we recommend reviewing the first one to two pages of results. 

The GIM search results page defaults to showing the most recent articles added to the database first. You may change this by clicking the Order by dropdown to select another organization of your search results. 

While reviewing the first pages of results, look for articles that fit your research question and gather keywords from the title and abstract to add to your search query. Also look for results that do not fit your research question and investigate why they are in your results. For example: 

• Are there keywords in your search query with two meanings?
  • If so, you may not be able to remove these irrelevant results from your search or you may be able to modify your search terms to capture the meaning you intended. 
• Is there a theme among the articles that are not relevant to your research question?
  • If so, is it possible to add a concept to your search to make it more specific or can you remove a keyword without losing many relevant articles at the same time? 

If you have many results, consider whether a database filter will help refine your search results. For example: 

• You may want to filter your results based on the type of study. When using GIM on a desktop computer, these filters appear on the left side of the page under Add Filters. 

Explore the filter options as you'd like, and keep in mind how they may introduce bias into your research. For example: 

• Adding a filter for English articles biases your research toward articles written in English or to projects with the funding for English translation. 
  • You may use a freely available translator (like DeepL Translator or Google Translate) to get the gist of what an article is about when evaluating your search results.

Perhaps while reviewing the results, you found that a particular concept within the results catches your interest more than others. Consider replacing part of the search with that concept if, for example, you're interested in contraceptive use in Togo, you might remove your keywords for Africa and use keywords for Togo specifically. If this revised search provides no or very few results, you have several options for proceeding:

• Check for errors in your search syntax (e.g., did an AND replace an OR by mistake? Did your parentheses move around or get deleted?).
• Add more keyword variations for your concepts, paying special attention to the new or changed concept that reduced your results. 
• You may want to expand your search beyond Global Index Medicus. 
• There may not be enough research on your topic and using a topic with more research may be a good fit. You may also take this as a reason to conduct primary research to develop the literature in this area. 

If there are too many results, consider whether changing the field tag for your keyword terms to title using ti:() OR ab:() instead of tw: in step 5.2 above will improve results. Keep in mind you will miss any articles that did not mention one of your keywords in the title or abstract. 

Searching is iterative. Your first search will not be perfect! Keep working through these steps to find relevant articles and potentially remove some of the irrelevant search results. Some irrelevant articles in your search results are inevitable; trying to remove all of them will result in missing out on relevant articles too. 

Not all of these points will apply to every type of research assignment, of course, but they’re a good way to tell yourself “enough is enough”:

1. Are you coming across the same information in multiple, credible sources (i.e. three or more)?
2. Have you already found relevant information in different types of sources (i.e. books, journal articles, government publications, newspaper articles – whatever is appropriate for your subject area)?
3. If you added a new angle or subtopic now, would it just complicate your argument rather than strengthening it?
4. Are you starting to collect information that isn’t exactly on your topic?
5. Are you running out of time to actually write/prepare your assignment?
6. Do you have enough information to cover the main points of your topic well (or support your thesis, if applicable)?

If you find yourself answering “yes” to most of these questions (where applicable), it’s probably time to move on.

- Katie Holmes, Beryl Ivey Library at Brescia University College, 2017