AMA Guides to the Evaluation of Permanent Impairment

For over 50 years, the AMA Guides to the Evaluation of Permanent Impairment have been the trusted source that physicians, patients and regulators rely on for fair and consistent impairment rating guidance and tools. More than 40 states and several countries rely on the AMA Guides® as the accepted authority to assess and rate permanent loss of function.

What's New for 2024
Evaluators familiar with the 2008 Guides will notice significant changes in the latest update. The grade modifiers have been replaced to address the feedback from multiple stakeholders, who found that these modifiers introduced an undesirable bias, reducing the fairness and equity of impairment values across various jurisdictions. Specifically, the grade modifiers, which used terms like "mild," "moderate," or "severe," lacked specificity and resulted in wide ranges of impairment values for similar functional losses. This led to reduced interrater and intrarater reliability, and a decline in accuracy, consistency, and reproducibility.

In place of the grade modifiers, the 2024 edition introduces specific individual elements (SIEs) of the clinical history, physical examination, and relevant clinical studies. Additionally, key elements have been replaced with specific diagnostic rows in the diagnosis-based impairment (DBI) tables, leading to more fair and equitable impairment values.

Evaluators are already familiar with the criteria in the diagnostic row, which are based on the traditional three components: clinical history, physical examination, and relevant clinical studies. As a result, all evaluators possess the skills necessary to match the objectively verified anatomical findings to the criteria in each diagnostic row.

• • The SIEs for clinical history include current clinical presentation; mechanism of injury; reported functional loss; functional outcome surveys; the impact of no treatment, appropriate treatment, or inappropriate treatment; and any preexisting impairments, diseases, conditions, illnesses, comorbidities, psychosocial factors, and considerations for the natural history of the diagnosis.
• • For physical examination, the SIEs cover traditional assessments such as appearance, sensory function, motor strength, and vascular supply.
• • The SIEs for relevant clinical studies include radiographs, MRI, CT scans, nerve studies, vascular studies, and laboratory tests.

By using specific individual elements (SIEs), evaluators can apply objectively verifiable criteria to confirm appropriate impairment values based on the International Classification of Functioning, Disability, and Health classes defined in the diagnostic rows. This approach ensures that impairment values are fair and equitable, accurately reflecting the individual's condition at the time of maximum medical improvement and the improvements provided by treatments.

The diagnostic rows list the necessary SIEs to determine the impairment value, enhancing the quality of impairment rating reports. Evaluators can now document the diagnosis and the SIEs present at maximum medical improvement (MMI) to determine the impairment rating. This method allows for easier review by both professional and nonprofessional evaluators, ensuring consistency and fairness across multiple jurisdictions.

What's New for Diagnoses
The diagnosis-based impairment (DBI) tables have been expanded to encompass a wider range of diagnoses, including new conditions, treatments, and medical advancements that were unavailable in 2008. This update ensures that the DBI tables are more comprehensive and up-to-date, allowing evaluators to consider a wider range of conditions and their respective treatments. As a result, impairment ratings are more accurate and reflective of current medical practices, improving the overall fairness and reliability of impairment evaluations.

Consistency
All three musculoskeletal chapters follow the same format and approach in the DBI tables. Sections and tables are specifically numbered to facilitate easy identification of the diagnostic row in the evaluator's report, establishing the specific individual elements of the clinical history (CH), physical examination (PE), and relevant clinical studies (CS) used to match the diagnostic row criteria.

The DBI tables include specific instructions to minimize the need to reference multiple sections or tables, eliminating the need to use grade modifier tables and reducing the need to "flip back and forth in the book” during an impairment evaluation. This streamlines the process, reduces errors, and improves the accuracy of impairment ratings. Clear guidance for adding or combining impairment values at different level is often incorporated into the DBI tables.

Vignettes
The 2008 vignettes have been updated to align with the 2024 method, reducing the need for additional training and enhancing reliability and consistency. Furthermore, new vignettes featuring complex clinical presentations (real-world examples) have been added to illustrate the 2024 method.

Getting Started
While the evaluator is encouraged to thoroughly read the entire chapter, valuable insights and detailed explanations are provided to support the instructions in the DBI tables. This comprehensive review ensures a deep understanding of the methodology and the rationale behind the updated approach, facilitating a more accurate and consistent application of the impairment evaluation process. Familiarity with the entire chapter will enhance the evaluator's ability to effectively use the DBI tables and apply the 2024 method to a wide range of clinical scenarios.

On behalf of the Guides Panel, we would like to thank the panel members, the five musculoskeletal subcommittees, contributors and reviewers, those who provided public comments, web access attendees, and the AMA Guides staff for their support in this update as listed in the Acknowledgments Section.