What is a Class I recommendation?

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Last updated: April 6, 2025View editorial policy

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From the Guidelines

A Class I recommendation is a strong clinical guideline that indicates a particular treatment, procedure, or intervention should be performed or administered because it has been proven to be beneficial, useful, and effective for most patients, with the benefits substantially outweighing the risks, as supported by the most recent guideline from 2017 1.

Definition of Class I Recommendation

A Class I recommendation is characterized by a strong strength of recommendation, indicating that the procedure or treatment should be performed or administered, with suggested phrases including "is recommended," "is indicated," "is useful/effective/beneficial," and "should be performed/administered" 1.

Key Characteristics

The key characteristics of a Class I recommendation include:

  • Benefit substantially outweighs risk
  • General agreement among experts that the intervention is appropriate
  • High-quality evidence from multiple randomized clinical trials or meta-analyses
  • Consistent demonstration of significant benefit over risk

Clinical Implications

When clinicians encounter a Class I recommendation in practice guidelines, they should generally follow this guidance for eligible patients, unless there are compelling individual circumstances that would make the intervention inappropriate, as noted in the 2011 ACCF/AHA guideline for the diagnosis and treatment of hypertrophic cardiomyopathy 1.

Evidence-Based Medicine

Class I recommendations form the foundation of evidence-based medicine, providing clinicians with confidence that implementing the suggested intervention will likely improve patient outcomes, and helping to standardize care across healthcare settings, as emphasized in the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1.

From the Research

Definition of Class I Recommendation

A class I recommendation is a designation given to a treatment or intervention that is supported by the highest level of evidence and is considered to be a standard of care.

Characteristics of Class I Recommendation

  • It is based on evidence from multiple randomized controlled trials or meta-analyses 2
  • It is recommended for all patients with a specific condition, unless there are contraindications 3, 4
  • It is considered to be a standard of care and is widely accepted by the medical community 5, 6

Examples of Class I Recommendations

  • Aspirin therapy for patients with acute myocardial infarction 3, 5, 6, 4
  • Beta-blocker therapy for patients with acute myocardial infarction 3, 5, 6, 4
  • Angiotensin-converting enzyme (ACE) inhibitor therapy for patients with acute myocardial infarction and certain other conditions 3, 5, 6, 4

Key Points

  • Class I recommendations are based on the highest level of evidence and are considered to be a standard of care
  • They are recommended for all patients with a specific condition, unless there are contraindications
  • Examples of class I recommendations include aspirin, beta-blocker, and ACE inhibitor therapy for patients with acute myocardial infarction 3, 5, 6, 4

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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