Erroneous Ratings: Part IV

Saturday, March 25, 2006 | 0

In the last article we examined some of the common reasons for erroneous ratings. This installment looks at how incorrect clinical assessment will result in an erroneous rating.

There are many potential rating errors resulting from inaccurate clinical or causation analysis. These include inappropriate diagnosis, rating prior to being at maximal medical improvement, using unreliable examination findings, not considering what is normal for the individual, and inaccurate causation assessment.

Incorrect clinical assessment can result in the rating of impairment for a condition that is not present or unrelated to the alleged injury. For example, the physician may label a patient as having, "complex regional pain syndrome" (CRPS) and rate for this disorder, whereas the more accurate diagnosis is "somatization." In the Guides certain diagnoses are not typically associated with ratable impairment, i.e. tendonitis or psychiatric illness; a physician attempting to inflate a rating may choose to provide another diagnostic label that would result in ratable impairment.

Assessing impairment prematurely will often result in an inflated impairment rating. The rating of permanent impairment cannot occur until the patient has achieved maximal medical improvement (MMI). MMI is defined on page 601 as, "a condition or state that is well stabilized and unlikely to change substantially in the next year, with or without medical treatment." Typically following an injury a patient will improve over time, improved range of motion and neurological function and resolution of ratable findings will result in a lower impairment rating. MMI is often not achieved until a minimum of six months to one year post injury. Cases that often require a longer time frame for resolution include carpal tunnel syndrome with ongoing neurological deficits, hand injuries, and head injuries.

An erroneous rating will occur if the rating is based on clinical findings that are erroneous. Findings must be reproducible if they are to serve as a basis for impairment rating. The Guides state in Section 2.5d on page 20:

* Two measurements made by the same examiner using the Guides that involve an individual or an individuals function would be considered consistent if they fall within 10% of each other. Measurements should be consistent between two trained examiners or by one observer on two separate occasions, assuming the individuals condition is stable.

Many clinical findings are not totally objective, i.e. independent of the examinee. For example, with range of motion impairment rating, the rating is based on findings of active motion, i.e. what the individual demonstrates. An individual may display less range of motion than actual capability. Neurological findings, such as reports of diminished sensation, are dependent on self report and an individual may demonstrate less strength than true capability. In that an individual can demonstrate less capability than they are truly capable of, however cannot demonstrate greater capability than this limit, inconsistent examination findings will nearly always result in greater impairment. Examiners vary in their clinical examination skills; therefore there may be a lack of reliability in demonstrating clinical findings.

The musculoskeletal chapters (Chapters 15 to 17) define standards for consistency. For example, in Chapter 15, The Spine, there is a lengthy discussion of the process of obtaining spinal range-of-motion measurements using an inclinometer. Section 15.8a, General ROM Method Measurement Principles, on page 399 provides emphasis with italics.

* Pain, fear of injury, disuse, or neuromuscular inhibition may limit mobility by diminishing the individuals effort, leading to inaccurately low and inconsistent measurements. The physician should seek consistency when testing active motion, strength, and sensation. Tests with inconsistent results should be repeated. Results that remain inconsistent should be disregarded. When the physiologic measurements fail to match known pathology, they should be repeated and, if still inconsistent, disallowed until documented evidence is provided for the abnormalities noted on the physical examination... The measurements and accompanying impairment estimates may then be disallowed, in part or in their entirety. There are multiple potential sources of error in a quantitative physical examination... The greatest source of error that occurs is due to test administrator inexperience or lack of knowledge"

Using the spine as an example, there are other findings that may not be reliable; including "spasm", "guarding", "non-verifiable radicular complaints" and neurological findings. It may be advantageous for physicians wanting to demonstrate the need for ongoing treatment to report findings that may not be observed by others. In reviewing a report it is imperative to determine whether the examination findings were reliable. This includes assessing whether the physician has performed the examination to determine the presence of consistent findings and comparing examination findings to other observations since the patient has been at maximal medical improvement; other sources of data may include physician records, physical therapy records, and surveillance.

Another common error is not considering what is normal for the individual. The Fifth Edition discusses in Section 1.2a Impairment the determination of normal. The Guides state on page 2 "when evaluating an individual, a physician has two options: consider the individuals health preinjury or preillness state or the condition of the unaffected side as "normal" for the individual if this is known, or compare that individual to a normal value defined by population averages of healthy people. The Guides uses both approaches." Section 16.4c Method for Motion Impairment Calculation states on page 453 "The measurements reported in the impairment tables and pie charts reflect the accepted average range(s) of motion for each joint. However, certain people can have either lesser or greater joint flexibility than average. It is therefore most important to always compare measurements of the relevant joint(s) in both extremities. If a contralateral "normal" joint has a less than average mobility, the impairment value(s) corresponding to the uninvolved joint can serve as a baseline and are subtracted from the calculated impairment for the involved joint. The rationale for this decision should be explained in the report." In this case the opposite extremity does serve as "normal" for this individual, therefore losses should be determined in relationship to this normal. Extremity evaluations should always include examination of both sides.

In the next issue of the ezine we will examine errors in causation assessment that lead to erroneous ratings.

by Chris Brigham.
Please contact Mindy Brigham for further information at 619-299-7377 or mbrigham@brighamassociates.com.

-----------------------------

The views and opinions expressed by the author are not necessarily those of workcompcentral.com, its editors or management.