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Treadwell's Service for Systematic, Scoping and Other Reviews

A guide to help with conducting comprehensive and non-comprehensive reviews

What is a comprehensive review?

"Comprehensive reviews" is an umbrella term. It refers to any review where the literature search is exhaustive and documented in a detailed and thorough way in accordance with accepted standards to avoid outcome bias. Conversely, a non-comprehensive review does not need to follow the same standards, is less rigorous and has a shorter time commitment. 

A systematic review is one type of comprehensive review. It is a review of a "clearly formulated question that uses systematic and explicit methods to identify, select, and critically appraise relevant research, and to collect and analyze data from the studies that are included in the review" (PRISMA). Statistical techniques (meta-analysis) may optionally be used to analyze the results of included studies of a systematic review. For biostatistics consultations, contact the MGH Division of Clinical Research or the Harvard Catalyst Biostatistics Consultation Service. 

Similar to how one would not embark on primary research without a protocol, one should have a protocol in place before initiating a comprehensive review.

The table below breaks down which review types are considered comprehensive and which are not:

Comprehensive Reviews  Non Comprehensive Reviews
Systematic Reviews Narrative Reviews
Scoping Reviews Critical Reviews
Umbrella Reviews  
Integrative Reviews  
Rapid Reviews  

It's important to have a good understanding of whichever review type you would like to pursue. Below are articles that talk more in depth about the differences between reviews. You can also use the "Which Review Is Right For You?" tool to help guide you in choosing a methodology.

What services does Treadwell offer?

Treadwell offers two tiers of review service, adapted from Harvard's model:

Level I: Acknowledgement

  • Initial consultation meeting
  • Offer advice on appropriate review methodology
  • Develop a Medline search strategy using controlled vocabulary and keywords
  • Identify and suggest other databases for extending search
  • Suggest citation and project management tools

Level II: Co-authorship

  • All level I services
  • Edit sections of the protocol that document the search
  • Translate Medline search into four or more databases 
  • Upload results into Covidence after removing duplicates
  • Create PRISMA-compliant search documentation and author search methodology for the manuscript
  • Review manuscript before submission and draft responses to peer reviewers or editors for questions regarding the search
  • Send instructions on how to retrieve full text PDFs


  • Due to the time-intensive nature of this work, a limited number of reviews can be worked on at a time so the service may not be available if maximum capacity has been reached.
  • As projects evolve, the librarian retains the right to change tiers to accurately reflect the nature of the work being conducted, as well as refuse co-authorship.
  • If you request more than one project, they will be worked on sequentially not concurrently.

I'd like to work with a librarian on my review project. How do I get started?

Due to overwhelming demand and not enough current staffing to handle it, we have a waitlist

Wait time is 4 weeks

If your project cannot wait, we suggest leveraging a librarian at a different institution if someone on your team has another affiliation or hiring a contract librarian if you have the funds. Below are resources outside of MGH that can help:

Courses that teach execution of a literature search:

How to find an independent contract worker to perform the literature search:

Intake Process

If you would like to be added to the wait list, fill out this form

Conducting Standards for Reviews

Learn how to conduct comprehensive reviews in our Process and Standards pages. Resources about other common review methodologies are listed below. 

Scoping Reviews

Scoping reviews serve to synthesize evidence and assess the scope of literature on a topic. Among other objectives, scoping reviews help determine whether a systematic review of the literature is warranted.

Umbrella Reviews

Systematic reviews of systematic reviews

Rapid Reviews

Rapid reviews omit parts of the systematic review process to speed up the review process. 

Integrative Reviews

Integrative reviews are most often seen in the nursing discipline.

Living Systematic Reviews

Living systematic reviews are continually updated reviews that may be used to synthesize rapidly evolving areas of research. 

Narrative Reviews

Covidence: Online Platform to Streamline Systematic Reviews

Treadwell provides access to Covidence, an online platform that aims to accelerate the systematic review process, at no cost to MGH employees. MGH employees can also invite individuals from outside of MGH to collaborate on Covidence projects. 

Covidence is accessible by computer or mobile device, and provides one convenient place to screen citations, assess risk of bias, and extract data. 

Access Covidence

To access Covidence, request an invitation here using your or e-mail address. Do not use your or address.

Have a MGH Covidence account already? Log in here.

Learn How to Get Started With Covidence

For videos and instructions to help you get started, see our support page in the Covidence Knowledge Base.