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How do I find articles that are in specific levels of the evidence pyramid?


The evidence pyramid is a visual reminder of both the quantity of research published and the quality. There are literally more articles and documents that fit in the lower levels of the pyramid, and fewer of the filtered resources toward the top of the pyramid. Searching any of the library’s article databases, PubMed, or Google Scholar will find articles up and down the pyramid.

  1. Some databases have more of one or other type of resource, so search the ones that work best. If you are searching for filtered sources toward the top of the pyramid, use the recommended resources in the Reviews, Guidelines, Protocols, and Care Bundles, oh my! guide.

Here’s a visual:

  1. Aside from making good choices among which databases to search, another tool to use to ensure you find articles which fall into a particular level on the evidence pyramid is to use or exclude search terms or subject headings which make it more likely that you would find what you need. If you know you don’t want systematic reviews, you can specify it in CINAHL or Proquest Nursing and Allied Health.

The above search includes the term hypothesis: many quantitative research studies begin with an hypothesis, which is given in the abstract. The search also changed the default “and” to “not” on the third line to exclude any abstract with the phrase “systematic review.”

The above search looks for a specific type of study.

  1. The last tool is simple, yet hard. Read the abstracts of the articles you find. Reading carefully is your best tool to determine what you are looking at. Read the abstract for clues like the names of statistical tests, the word hypothesis, words that describe study types. If the abstract says the article is a research protocol and you need to find a research report, don’t use that article. If the article says it used results from a focus group to describe characteristics of a group, but you need a quantitative article, don’t use that article. And if an article is highly informative, but doesn’t mention that the authors conducted research, it’s likely an expert opinion article, not a research article.


More information you can use is here:

What are filtered and unfiltered sources of evidence on the evidence pyramid?

Evidence Pyramid and Appraisal Tools

Reviews, Guidelines, Protocols, and Care Bundles, Oh My! 

How do I find qualitative or quantitative research articles?

What are primary or secondary sources?

What is peer review?


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