Thumbnail: woodpecker-inverted

The Challenge of Zheln

Summary #1 on
5 minute read

Zhelnov P. The challenge of Zheln. Zheln. 2020 Sep 20;36–38(1):s1e5. URI:


  • The amount of published research has long been unmanageable, so Zheln helps tackle it
  • On Zheln, every systematic review daily added to PubMed gets a critical appraisal
  • Zheln provides rigorous conduct appraisal involving focused replication attempts
  • Free from affiliations & crowdfunded, Zheln stands out as truly independent research
  • Zheln features fully transparent production with public raw data & project management

Why Zheln?

Hi, this is Pavel Zhelnov, the founder and the workforce of Zheln. I have launched this project in the hopes of bringing evidence closer to practice—the clinical practice, in the first place, but also to other activities associated with intervention into a human life, such as education, business, or policy.

Currently and for more than 10 years now, a wide gap has been recognized between the fast pace research is published and the limited capacity of evidence-based practitioners to promptly process it while also separating the practice-changing wheat from the chaff. And to my utmost disappointment, it is in contrast to a variety of solutions available that the call for a dramatic change is out in 2020.

Well, anyway, here I bring a change:

Every systematic review daily added to PubMed will get a rigorous, independent, and open-access critical appraisal.

This is the Zheln’s Mission.

This is the way.

How Is Zheln Different?

The idea of preappraised evidence summaries is all but new. Anyone in the field of evidence-based medicine is well aware of the ACP Journal Club, Cochrane Clinical Answers, or now legacy DARE summaries, just to mention a few. Not all of them cover secondary research only as Zheln does.

Anyway, I never found a resource that would have the following features at the same time (but if you did, I invite you to publicly discuss it on Twitter):

  • Exhaustive research coverage
  • Rigorous conduct appraisals with replication attempts
  • Independence proven by full process transparency
  • Full Open Access
  • Easy to use

Then, in the Summer 2019, I felt like the launch of another was warranted; however, one more year was needed for me to get free of institutional agendas and set a course for this undertaking.

So What Does Zheln Offer?

Exhaustive Research Coverage

Nearly All Systematic Reviews Indexed by PubMed

Rigorous Conduct Appraisals with Replication Attempts

Zheln Review Appraisal in 10 Steps:

Step 1. Download All Records from a Daily Update for the Replicated Version of PubMed Systematic Subset

5,609 records uploaded to date (Sep 2 thru Sep 13, 2020).

Step 2. Record Appraisal: Does Meet Shojania & Bero 2001 True Positive Criteria for Systematic Reviews by Either Title or Abstract?

Just a couple of records have got past this stage by now because Zheln record screening methods are still in development. Namely, I’m developing a system to quickly process records in the Zheln format. Currently, development of the Zheln website was a priority, so the appraisals themselves got somewhat overdue. Follow the progress on the public Zheln kanban!

Step 3. Collect Full Text or Other Review Reports for the Record

Step 4. Full Appraisal: Does Generate Pragmatic Evidence Directly Relevant to Evidence-Based Practice?

One appraisal has been started by now. I will complete it as soon as I have a good record triage system in place, because 5k+ records awaiting appraisal need to be processed ASAP.

Step 5. Full Appraisal: Is Duplicate?

Step 6. Full Appraisal: Did Pass or Fail Replication?

Step 7. Full Appraisal: Has Critical Conduct Flaws?

Step 8. Like or Dislike by Zheln

Step 9. Summarize Practical Implications

Step 10. Publish the Appraisal & Call for Crowdfunding

No Institutional Affiliations

 I’m an Individual Researcher

Supported by Crowdfunding Only

 Patreon and  PayPal

Full Process Transparency

 Methods and  Kanban

Easy & Free to Use

Open Access Web Banner CC BY-SA Web Banner

 Search for Appraisals,  Browse by AMA Specialty, or  Read Biweekly Appraisal Summaries

Star Wars!

 Subscription Levels Based on Star Wars and  Customizable Appraisal Icons

Get in Touch Now or Get Back on Wed, Sep 23

Email, Twitter, Instagram, Facebook, or Telegram