Evidence Synthesis: Home

Evidence synthesis is a process of combining and interpreting individual studies to understand a particular topic. This process creates a rigorous and transparent foundation for using research evidence in decision-making.

The key to evidence synthesis is transparent methodology including how studies are chosen, evaluated, analyzed, and how the strength of the evidence is determined to answer the research questions.

Studies show that librarians produce high quality search strategies and minimize bias in evidence synthesis projects.^1-3 Librarian roles in such projects can also span planning, question formulation, source selection, and citation management.⁴

Midwestern University librarians offer various levels of assistance with evidence syntheses. Refer to the library policy below for more information:

(updated Feb 2025)

Before contacting the library to arrange a meeting with a librarian, all prospective evidence synthesis researchers should be familiar with the content of the MWU Library Evidence Synthesis Guide to come prepared for an efficient discussion.

Midwestern University faculty, staff, students, and fellows/residents may request consultative or mentorship level assistance for evidence syntheses including systematic reviews, scoping reviews, and rapid evidence assessments. Collaborative level is limited to faculty and others as decided on an individual basis. MWU librarians are unable to contribute to clinical practice guidelines or consensus guidelines.

At the first meeting, once librarian participation level is established at either the consultative level or the mentorship level, all research participants will be expected to sign a research agreement which states that they understand the expectations of each member of the team as well as the timing of the project.

Consultative Level – no more than 3 sessions or 3 hours

Librarians provide face-to-face or online consultations* covering the processes and best practices for conducting an evidence synthesis. It is designed to get the researcher started. The principal investigator must meet with the librarian and the student team early in the process so that the whole team has the same understanding and expectations, no later than the second group meeting.

Please note:

• The librarian does not perform the actual search, assist with writing the search methodology, or data management
• If the faculty member plans to have students do the searching, we recommend moving to our mentorship level.
• Acknowledgement of librarian contribution upon publication is required.

The librarian will:

• Assist in determining the research question and which type of review best answers it
• Provide consultation on the review process
• Give advice on identifying controlled vocabulary and keywords
• Provide recommendations for databases and other resources to search for evidence using the MWU library databases
• Give advice on citation management methods and tools

*A consultation does not guarantee immediate service assistance.

Mentorship Level—recommended for students not working with a faculty member

Librarians work with student groups with or without the direction of a principal investigator.   Acknowledgement of librarian contribution upon publication is required. 

• Multiple meetings will walk through steps of the review as the project moves forward
  • Initial meeting (first or second) must include the Principal Investigator and all students/team members so that everyone has the same understanding of the project being undertaken
  • Subsequent meetings must include the entire team to keep up to date on steps taken and needed on the project
  • Group members will each have a copy of the research agreement to keep on task with their contribution expectations

The Librarian will:

• Assign responsibilities to group members to complete for each meeting, when necessary
• Guide team on locating controlled vocabulary (Emtree, MeSH, etc), tiab terms, and how to translate final search terms
• String together search strategy and translation(s) for final run
• Run searches in each database with students and transfer results into Covidence and/or Endnote
• Recommend a workflow for retrieving full text articles

Collaborative/Coauthor Level

Librarians’ highest priority is supporting students through instruction in information literacy, literature searching, and research. When a collaborative level evidence synthesis search request is received, the librarians assess the topic and the proposed timeline to see if workflow allows time to complete the search by the proposed deadline, and, if necessary, clarify the flexibility of the research team’s timeline. An MWU librarian may not be able to participate if timing and primary responsibilities do not allow it.

Librarians conduct expert searches for systematic reviews and other evidence syntheses and document them in the methods section. As members of the research team, librarian efforts will be recognized with co-authorship of the manuscript or a combination of negotiated terms which will include published acknowledgement.

Creation of a comprehensive search and translating into additional databases can take a minimum of three months. Researchers should factor this commitment into the publication timeline.

The librarian will:

• Help locate recently published protocols or SRs on the topic
• Identify key concepts using PICO (Patient/problem, Intervention, Comparison, and Outcome) or similar methods
• Identify appropriate search terms: controlled vocabulary and keywords in conjunction with SR team members
• Test and refine search strategy then translate it for multiple databases as required/requested by SR team members
• Document line by line database search strategies and grey literature
• Pull/Export references retrieved from multiple sources
• Recommend a workflow for retrieving full text articles
• Provide updates to search results as work progresses and prior to the final write- up
• Write the literature search methods section for publication, including preparing the PRISMA flow chart
• Review methods section of the manuscript

1. Rethlefsen ML, Farrell AM, Osterhaus Trzasko LC, Brigham TJ. Librarian co-authors correlated with higher quality reported search strategies in general internal medicine systematic reviews. J Clin Epidemiol. 2015;68(6):617-626. doi:10.1016/j.jclinepi.2014.11.025
2. Meert D, Torabi N, Costella J. Impact of librarians on reporting of the literature searching component of pediatric systematic reviews. J Med Libr Assoc. 2016;104(4):267-277. doi:10.3163/1536-5050.104.4.004
3. Rethlefsen ML, Murad MH, Livingston EH. Engaging medical librarians to improve the quality of review articles. JAMA. 2014;312(10):999-1000. doi:10.1001/jama.2014.9263
4. Spencer AJ, Eldredge JD. Roles for librarians in systematic reviews: a scoping review. J Med Libr Assoc. 2018;106(1):46-56. doi:10.5195/jmla.2018.82