Fractured brain being analyzed by a doctor.

IMPACT Model: Can It Predict TBI Outcomes for Your Loved One?

Beau Callahan in Health & Wellness December 2025 • 4 min read.

"Exploring the Use and Misuse of Prognostic Models in Traumatic Brain Injury (TBI) Care"

When a loved one suffers a traumatic brain injury (TBI), families face agonizing decisions about their care. Doctors often rely on their experience to estimate a patient's long-term prognosis. But what if there was a tool to help? The IMPACT model is a widely-used tool intended to predict outcomes in TBI cases.

However, a recent study reveals a significant gap between the IMPACT model's intended use and how doctors actually apply it in clinical practice. Many express concerns about its accuracy and applicability to individual patients.

This article dives into the findings of this study, exploring the perceptions of physicians regarding the IMPACT model, its potential benefits, and the reasons why many are hesitant to rely on it when communicating with families.

The IMPACT Model: A Research Tool or Bedside Guide?

Fractured brain being analyzed by a doctor.

The study, which involved interviews with 20 attending physicians across various specialties (neurosurgery, neurocritical care, trauma surgery, and palliative care), found that only 60% were even aware of the IMPACT model. Among those, even fewer used it consistently to determine a patient's prognosis.

A major concern voiced by physicians was that the IMPACT model, and similar outcome scores, are primarily research tools. They were designed to inform clinical trial design, not to dictate treatment decisions for individual patients at the bedside. Applying population-based data to a single person's unique circumstances raised ethical red flags for many.

Intended for Research: The IMPACT model was designed to analyze clinical trial data, not to make individual predictions.
Individual Factors Matter: The model doesn't account for unique patient characteristics.
Ethical Concerns: Applying group data to individual cases can be misleading.

One physician stated, "I am always very scared when I hear of colleagues trying to use the IMPACT calculator or the CRASH calculator. These things were never designed for clinical decision making, they were designed to inform clinical trial design."

Finding a Balance: Using Data Wisely

While the IMPACT model has limitations, some physicians found it helpful in reducing variability in opinions among different specialists. In a complex and emotionally charged situation, having a common reference point can be valuable.

However, the study also highlighted a significant concern: that presenting statistical probabilities to families can be misleading. Many physicians worried that families, already under immense stress, might misinterpret the numbers, clinging to false hope or making decisions based on incomplete information.

Ultimately, the study underscores the need for a balanced approach. Prognostic models like the IMPACT model can be useful tools, but they should never replace careful clinical judgment, consideration of individual patient factors, and open, honest communication with families. Further research and improved models are needed to provide more accurate and personalized predictions in TBI care.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1177/2381468318757987, Alternate LINK

Title: Should We Use The Impact-Model For The Outcome Prognostication Of Tbi Patients? A Qualitative Study Assessing Physicians’ Perceptions

Subject: Public Health, Environmental and Occupational Health

Journal: MDM Policy & Practice

Publisher: SAGE Publications

Authors: Jesse Moskowitz, Thomas Quinn, Muhammad W. Khan, Lori Shutter, Robert Goldberg, Nananda Col, Kathleen M. Mazor, Susanne Muehlschlegel

Published: 2018-01-01

Everything You Need To Know

What is the IMPACT model?

The IMPACT model is a tool used by medical professionals to predict the outcomes of patients who have suffered a Traumatic Brain Injury (TBI). It is intended to aid in understanding the possible long-term effects of a TBI.

Why is the IMPACT model important?

The significance of the IMPACT model lies in its potential to provide a standardized approach to predicting outcomes in TBI cases. This is important because it could help reduce the variability in opinions among different specialists involved in a patient's care. However, the primary intention was to inform clinical trial design, not individual patient care.

What are the main limitations of the IMPACT model?

The primary limitation of the IMPACT model is its lack of consideration for individual patient factors. While the model uses data to determine outcomes, it was designed to analyze clinical trial data. Its use can raise ethical issues when applied to an individual patient due to the uniqueness of each case.

Why are doctors hesitant to use the IMPACT model?

Physicians are hesitant to rely on the IMPACT model because it was primarily designed for research purposes, not for making individual patient prognoses. They are concerned about the model's accuracy and applicability to individual patients, and that it does not take into account unique patient characteristics. Using population-based data to predict outcomes for a single person raises ethical concerns for many physicians.

How can the IMPACT model be helpful?

While not a primary goal of the IMPACT model, some physicians find it valuable in reducing the variability in opinions among specialists. In highly stressful situations, a common reference point, like the IMPACT model, can be helpful in discussions about a patient's care.