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Evidence Grading
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What is an evidence grade?

An evidence grade is given to a clinical study based on the quality of evidence presented in that study. Two major factors are considered when applying an evidence grade—the quality, which we define as validity, and strength, which we define as the benefit versus risk ratio.

What are the different evidence grades that VerusMed assigns to each clinical news brief?

There are 4 different grades — Level 1, 2, 3 and 4. Each evidence grade represents a different level of quality:
  • Level 1 - High Quality - Randomized controlled trials (RCTs; properly designed) with low false-positive and low false-negative errors (high power). Systematic reviews and meta-analyses of multiple, well-designed RCTs.
  • Level 2 - Moderate Quality - Evidence obtained from at least one well-designed experimental study. Randomized trials with high false positive and/or negative errors (low power). Prospective cohort study.
  • Level 3 - Low Quality - Evidence obtained from well-designed, quasi-experimental studies such as non-randomized, controlled, single-group, pre-post, cohort, time, or matched case-control series.
  • Level 4 - Very Low Quality - Evidence from well-designed, non-experimental studies such as comparative and correlational descriptive and case studies. Evidence from case reports and clinical examples. Expert opinion.

What are the factors that VerusMed uses to grade each article?

There are a number of factors that one needs to consider when assigning an evidence grade. Each clinical news brief that VerusMed produces will receive a level 1, 2, 3 or 4 grade based on these characteristics of the clinical study:
  • Study design — therapeutic, prognostic, diagnostic or economic/decision analysis
  • Number of study patients and the percentage of follow-up
  • Statistical power
  • Bias and influence
  • Effect size
  • Balance of benefits and risks

Can you tell me more about VerusMed's evidence grading system?

To further enhance the value it provides its readers, VerusMed implemented a comprehensive evidence-based medicine grading system in which each of its clinical news stories will be reviewed for quality of evidence and receive an evidence grade. VerusMed's evidence grading system is cutting-edge and in line with the U.S. Preventive Services Task Force (USPSTF), the American Medical Association, British Medical Journal, the Agency for Healthcare Research and Quality (AHRQ), the Cochrane Collaboration, among others.

Why has VerusMed implemented an evidence grading system?

VerusMed understands that physicians are starved for time and highly value knowing the quality of the literature they read. We believe that adding an evidence grading symbol next to the headline of each of our clinical news briefs will increase the value of each article and it will help physicians save time. Based on the grade that is assigned, physicians can decide whether they want to continue reading the article or reference it for future reading, whether the evidence should be applied to their clinical practice and whether they want to consider the evidence when making new decisions about patient care.

Why is it important to grade medical evidence?

Medical evidence, or the recommendations that are based on the evidence, can be of different quality. Sources of evidence range from small laboratory studies or case reports to well-designed large clinical studies that have minimized bias to a great extent. Since poor quality evidence can lead to recommendations that are not in a patient's best interest, it is essential to know whether a recommendation is strong (we can be confident about the recommendation) or weak (we cannot be confident).

How was VerusMed's evidence grading system developed?

Dr. Jeff Andrews, VerusMed's Editorial Advisory Board Chair and Senior Physician of the Vanderbilt Center for Evidence-Based Medicine, developed VerusMed's evidence grading system. He used standards created by the internationally recognized Grading of Recommendations Assessment, Development and Evaluation Working Group, also known as GRADE. (, of which he is a member.

Who grades VerusMed's clinical news briefs?

VerusMed's experienced team of medical writers and editors are responsible for grading each article.