For some doctors, the world of impairment ratings creates fear and anxiety – or on the other end of the spectrum, an adrenaline surge and battle-ready emotions. Little is taught in most chiropractic colleges on impairment ratings; and how they impact the life of a patient and reflect on the competence of the DC caring for the injured patient.
Impairment, Disability & Residual Symptoms: There's a Difference
Let's clarify the difference between impairment, disability and possible continued residual symptoms. Maximum medical improvement (MMI) has a factor in determining the permanent impairment itself. MMI is the date from which further recovery or deterioration is not anticipated, although over time (years), there may be some expected change. MMI is the condition or state in which the patient is stabilized and the condition unlikely to change substantially in the next year with or without treatment. This could be determined months or years after the initial date of injury.1
It is only from this MMI date that the permanent impairment rating can be determined in accordance with the AMA Guides to the Evaluation of Permanent Impairment (5th or 6th edition). Key principles of permanent impairment are that the impairment is stable, static or plateaued. Permanent impairment does not preclude the patient from receiving ongoing treatment after MMI. It is a clinical decision based on the doctor's analysis.
You can only rate the current impairment. You cannot speculate and attempt to rate any future impairment that might change years down the road. You can only rate the impairment that exists today after the condition has reached MMI.
Disability is an alteration of an individual's capacity to meet personal, social or occupational demands, or statutory or regulatory requirements, because of an impairment.2 Impairment does not equal disability. An impaired individual may not have a disability. Disability involves many intangibles.
Functional demands and motivation are both links between impairment and disability. You must take the person into account for disability regarding their mental and social adaptation, their occupation and how they as a person are impacted. Impairment assessment is a necessary first step for determining disability.
Ongoing symptoms or residuals are subjective, but can certainly be valid and should be described. A person may have no ratable impairment and no disability, but they can have ongoing residuals. Permanent impairment can only be just that. You cannot create an impairment rating unless it is at MMI and it is permanent via the definition in the AMA Guides.
Impairment percentages derived from the Guides criteria should not be used as a direct estimate for disability. However, impairment percentages do estimate the extent of the impairment on whole-person functioning, whether physical or mental; and account for basic activities of daily living, not including work.3
The Guides only apply to permanent impairment, as they attempt to assign a percent of permanent impairment for the individual's whole body. The purpose is to convert a human pathology or disease into a number and then convert that number into a monetary award. The Guides provide rules to evaluate patients with injuries or illnesses to translate this evaluation into an impairment number, and in so doing, assist legal and other compensation systems in the calculation of that monetary award.
This internationally accepted methodology published by the AMA Guides is accepted in almost all states' court systems, as well as countries across the world. Some state worker's compensation statutes recognize the 5th edition, while others have upgraded to the 6th edition and some accept both. There is a difference in state regulatory rules governing worker's compensation that are specific as to which edition they accept, whereas most all states allow both editions for personal-injury cases. Chiropractors can perform impairment ratings using the AMA Guides.
The AOMSI Method
One area in both editions of the Guides that is extremely easy to ascertain a whole-person impairment rating is the AOMSI method. This is applicable to most DCs caring for personal-injury cases resulting from an automobile collision affecting the cervical spine. Using modernized software with your digital X-ray or plain-film cervical spine flexion / extension lateral views, you can have the software automatically measure the potential for anterolisthesis or retrolisthesis of one vertebra over another and make a determination for a potential ratable impairment. This permanent impairment can range from 4-25 percent if the difference is 3.5mm, depending on the 5th vs. 6th edition.
AOMSI is the most reliable and standardized method of determining if spine ligamentous laxity or injury is evident, separate from the disc. The patient may not have enough laxity with measurable translation or angulation to qualify for the impairment rating, but even if it is 2mm compared to the 3.5mm for the rating qualification (5th edition), they still have objective, measurable evidence of abnormality and injury to the ligaments.
Thus, the translation measurement length has merit in the radiology report to prove injury, but it may not be severe enough to warrant the permanent impairment rating. The findings could be ratable, abnormal or normal measurements. The images are worth their weight in gold to provide evidence of ligamentous injury.
An MRI does not show this injury, as the flexion and extension views are required by the Guides for plain-film (digital) images. It is important to note that more than one segmental level in the spinal region could have a ratable impairment measurement. Some patients may have three or four vertebral motor units that might add more of a percentage to their impairment. Multiple spinal segment motor units could be ratable and anther motor unit could be abnormal, adding a combined value of permanent impairment to the whole person.
Monetary and Recovery Benefit
For a patient suffering from a personal injury, especially if they are about to enter a legal battle, an impairment rating can be the key to not only determining a monetary award, but also to helping devise a recovery plan. If they understand their injury and what the recovery plan is, compliance goes up and confidence in the DC is achieved.
Now that you know the importance of impairment ratings and how much they can help patients, it is time to get in the game. In a future article, I will take things a step further and take a closer look at how to deliver an effective impairment rating report.
References
- Andersson GBJ, Cocchiarella L (authors and editors). AMA Guides to the Evaluation of Permanent Impairment, 5th Edition. American Medical Association, 2000; pages 2 and 601.
- Andersson GBJ, et al., Op cit, page 8.
- Andersson GBJ, et al., Op cit, page 13.
Click here for previous articles by Steven Kraus, DC, DIBCN, CCSP, FASA, FICC.