MBI 361: Epidemiology: Finding Original Research
What are articles and where can I find them?
When your professors say something like "find five original research articles for your reference list", they are typically asking you to track down peer-reviewed publications from an academic or research journal. These journals usually have names like American Journal of Epidemiology, Environmental Health Perspectives, or Annual Review of Public Health.
There are hundreds of journals for different subjects and disciplines, so to save researchers time and energy trying to search through all of them individually, many of them are collected and made available through literature databases like BIOSIS Citation Index or PubMed. These databases offer streamlined searching and in many cases also provide access to the full-text of articles. In cases where the full-text is not available in that database, the Libraries often can provide access through other resources.
Primary vs Secondary Research
Remember that you will need to find at least 3 primary research articles for your proposal. Don't forget how to distinguish them from secondary research (and other types of articles).
| Primary Research | Secondary Research |
|---|---|
| Typically follows IMRAD format (Introduction, Materials & Methods, Results, and Discussion) | Typically has an introduction; other section headings will vary |
| Reports on original research or data | Summarizes, analyzes, and/or synthesizes original research, but does not report on any new findings |
An easy way to filter out most (not all) review articles is to add the phrase "NOT review" to the end of your database search. It will not be a perfect filter, but it will help save you some time.
Keyword searching using Boolean operators
Keywords
Keep in mind that the literature databases you will most likely be using do not function like Google or other search engines. Google relies on natural language processing to find quick answers; literature databases require you to be a little more thoughtful and purposeful with your search strings in order to pull together sources for in-depth research. You will have better luck finding what you need if you have a basic understanding of keyword searching using Boolean operators.
A basic keyword search in most databases will look for your terms in a few different places, most often in the article title, author, subject terms, and abstract fields. Keep in mind that, with very few exceptions, literature databases will not search in the full-text of an article! So if you want to find a wide array of sources on a particular topic, you will need to spend a little time brainstorming synonyms for some of your keywords.
VIDEO TUTORIAL: How to Search: Topic Breakdown
Boolean operators
Once you've got your starting list of keywords, you need to think about how to input them into the database's search interface, which often requires a basic understanding of Boolean operators and how they work. Simply put, Boolean operators tell the database how the keywords you're searching for are or are not related. The operators you'll want to become familiar with are OR, AND, and NOT. (Note: you don't have to capitalize your operators when you go to type in your search strings, but it can help visually separate your terms and is highly recommended.)
| Boolean Operator | When to use it | Example search string | What it does |
|---|---|---|---|
| OR | Use OR when you want to search for synonyms or similar concepts | vaccination OR inoculation |
Will bring back results that mention either "vaccination" or "inoculation". Will increase the number of search results; search is more comprehensive. |
| AND | Use AND when you want to connect two or more different concepts | cancer AND lethargy |
Will only bring back results that mention "cancer" together with "lethargy" (but not necessarily adjacent to each other). Will decrease the number of search results; search is more focused. |
| NOT | Use NOT when you want to exclude a concept from your search results. Use very sparingly! | dementia NOT Huntington |
Will bring back results that mention "dementia", but will exclude those that mention "Huntington". Best to only use if you notice the same irrelevant concept coming up in your search results, as it may potentially exclude some relevant information. Will decrease the number of results. Order matters with this one! "dementia NOT Huntington" will bring back a different set of results than "Huntington NOT dementia". |
VIDEO TUTORIAL: How to Search: Boolean Operators
Advanced search techniques
There are lots of other techniques you can use to effectively and efficiently search literature databases. Most will allow you to use all the techniques listed below but may have slightly different characters or syntax. Be sure to check the databases' help pages to find the correct syntax for each resource!
| Strategy | What it does | Example |
|---|---|---|
| Truncation |
Uses an asterisk to search for results that include the selected prefix with any word endings VIDEO TUTORIAL: How to Search: Truncation |
nurs* Will include results that mention "nurse", "nurses", "nursing", etc. |
| Wildcards |
Uses a symbol (most often $ or #) to search for terms that may have alternate spellings or additional characters. Check the help page for the database you're searching to make sure you're using the correct symbol. |
an$esthesia Will include results that mention "anesthesia" (American spelling) or "anaesthesia" (British spelling) |
| Phrase searching |
Uses quotation marks to enclose a group of terms that must show up exactly as typed. VIDEO TUTORIAL: How to Search: Phrase Searching |
"cancer fatigue" Will only include results that mention "cancer fatigue" exactly (but not necessarily "cancer-related fatigue"). |
| Proximity searching |
Uses an operator and a number (e.g., "N3", "NEAR/3") to find terms that appear in close proximity to each other. Some databases, like PubMed, do not allow for proximity searching, and others use different syntax. Be sure to check the help page for the database you're searching to make sure you're using the correct syntax. VIDEO TUTORIAL: How to Search: Proximity Operators |
blood N3 collection Will include results that mention "blood collection", "collection of blood", "blood was collected", etc. |
| Nesting |
Uses parentheses to group terms and more effectively use Boolean operators. VIDEO TUTORIAL: How to Search: Boolean Operators (starting at 2:09) |
(cancer OR neoplasm) AND (chemotherapy OR radiation) Will return search results that mention "cancer" together with either "chemotherapy" or "radiation", as well as "neoplasm" with either "chemotherapy" or "radiation". |
| Subject headings | Uses predefined subject terms (also called controlled vocabulary) to help account for different spellings, synonyms, and other related concepts. Typically more limiting than keyword searching. Different databases use different terms, so be sure to check the resource's thesaurus to select the best headings. |
"dementia"[Mesh] Will return search results that have been tagged with the Medical Subject Heading (MeSH) term "dementia". MeSH is used primarily in PubMed; other resources have similar headings. |
Key literature databases for epidemiology
These are some of the best resources for finding literature in epidemiology and public health, but is by no means an exhaustive list.
- PubMed This link opens in a new windowPubMed is the National Library of Medicine's (NLM) freely accessible interface to the MEDLINE bibliographic database, covering the fields of medicine, nursing, dentistry, veterinary medicine, biomedical engineering, the health care system, and the basic biomedical sciences.
- BIOSIS Previews This link opens in a new windowBIOSIS Previews, accessed via Web of Science, combines journal content from Biological Abstracts with supplemental, non-journal coverage from Biological Abstracts/RRM (Reports, Reviews, Meetings). Specialized indexing helps you discover more accurate, context-sensitive results. Use Web of Science to perform a cited reference search, where you can look up an article and see how many times it has been cited. Users may encounter content in this database the library has not purchased.
- Web of Science (Core Collection) This link opens in a new window
NOTE: If prompted, please enter your MU credentials. Do not select “Institutional Sign In.” Clearing web browser cookies and cache may also fix access issues.
Use Web of Science to perform a cited reference search, where you can look up an article and see how many times it has been cited. The Web of Science Core Collection includes the following databases: Science Citation Index (1900-present), Social Sciences Citation Index (1900-present), Arts & Humanities Citation Index (1975-present), Conference Proceedings Citation Index (1990-present), Book Citation Index (2005-present), Emerging Sources Citation Index (2005-present), Current Chemical Reactions (1985-present), Index Chemicus (1993-present). Users may encounter content in this database the library has not purchased.
Get to Full Text with Find It!
Most literature indexes do not have the actual journal articles included within them. Instead, these indexes just contain information about the article, e.g. titles, authors, abstract.
When you find an article of interest in an index, click the "Find It" button by that entry to get to the full text. If we have a subscription, "Find It" will provide a link to the journal article. (Or if we have the print, it will provide a link to the catalog with the location and call number.)
(A few databases, like Academic Search Complete, include full text for some articles. These databases may allow you to search only for articles available in full text, but be aware that you are only searching a small portion of the articles we actually subscribe to.)