Terminology & Explanations

Terminology in the medical-legal field can be confusing.
Let’s make sure we’re all on the same page.

Independent Medical Examination (IME)

IMEs are often requested to help in matters of dispute. IMEs differ from your routine patient encounter in that the physician is not entering into a treatment relationship with the patient. The physician is usually provided records to review, obtains a history from the patient and performs a pertinent physical exam. The IME physician then answers the questions raised by the referral source typically by generating a report which details their findings. Our opinions are based on our experience and training as well as the latest science in the medical literature.

Most often the IME physician is requested to address issues of causation. Questions regarding previous and future treatment needs are also often answered. Determining if a patient has reached a point of Maximum Medical Improvement (MMI) can be another issue. If no further medical treatment will improve the patient’s condition, then they likely are at MMI. If so, a Permanent Partial Impairment (PPI) may be requested. The patient’s capacity to function can also be addressed as disability issues may impact their future earning potential.

Diagnosis is Key

To properly fix a problem one must first diagnose what is causing it. Often, when medical problems are misdiagnosed, they progressively worsen ultimately resulting in permanent damage or death. An old adage in medical school was that 80% of making a diagnosis lies in the history. If you ask the right questions and listen well to the patient’s answers, many times the diagnosis can be made before any fancy, expensive tests are employed. A skillful exam will also help to pinpoint the diagnosis. And yes, at times diagnostic imaging or lab tests are relied upon to confirm or exclude a diagnosis. The sooner an accurate diagnosis is made the better the prognosis, as prompt appropriate treatment has a better chance of resolving the condition. Diagnosis is also important for determining causation. Once a diagnosis has been made, one can determine if it is plausible that a particular event caused the diagnosis.


Determining causation is one of the most common questions asked of the IME physician. This may seem like a straight-forward task but when the individual has a pre-existing condition or when the condition is the result of a secondary effect of an injury, making that determination can quickly become complicated. The physician may use terms such as medically “probable” or “more likely than not” when opining on causation. The medical-legal standard is always some variant of what is probable or likely – if converted to percentages, it would indicate a greater than 50% likelihood. When determining causation, we look to the guidance provided by the American Medical Association and specifically, the AMA Guides to the Evaluation of Disease and Injury Causation. We have adapted their methodologies and use three main criteria to make causation determinations.

The first criterion is to determine whether the incident or trauma could have caused the outcome or diagnosis. The second criterion is to determine whether there is a strong temporal relationship between symptom onset and the incident. The third criterion in establishing causation is to determine whether the diagnoses could be explained by a more plausible cause. In using this approach, we aim to have a systematic and non-biased approach to sorting through the often-complex elements of an individual’s medical history to arrive at a causation determination.


Impairment is defined as a significant deviation, loss, or loss of use of any body structure or function in individual with a health condition, disorder or disease. Impairments are determined as a percentage of the body part involved and then converted to a percentage of the whole person. This is commonly referred to as a permanent partial impairment (PPI). An injury may result in an impairment (PPI rating) from 0 to 100% of the whole person depending on the severity of the condition. Impairment ratings are defined by anatomic, structural, functional and diagnostic criteria. An accurate exam is important in determining impairment as is the specific diagnosis. Generally, impairment should not be determined until the patient has reached a point of maximum medical improvement (MMI).

Ultimately, the system for determining impairment should be reliable so that different physicians arrive at consistent impairment ratings when assessing the same individual. To achieve consistency, the American Medical Association has been publishing The Guides to Evaluation of Permanent Impairment since the 1950s. The most recent edition is the Sixth Edition published in 2008. This addition continues to emphasize diagnosis as a key contributor to determining the impairment rating.


Often, the IME physician is asked to determine disability. Disability is the alteration of a person’s capacity to meet personal, social, or occupational demands or statutory requirements because of impairment. Disability is a relational outcome, contingent on the environmental conditions in which activities are performed. Whereas impairment is a loss or derangement of any body part or organ system. The effect of one’s impairment on their ability to perform functionally determines their level of disability. Disability is usually determined with respect to a specific job or task. It can be partial or a total inability to work in any capacity.

Sometimes, the question of duration or permanency of the disability may be raised. When considering a patient’s ability to function, one must weigh the significance of their condition, whether they have rehabilitation potential or if accommodations will allow them to function in the workplace. Ultimately the recommendation regarding an individual’s ability to work should be consistent with their diagnosis and the associated physical findings and symptoms.