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New Injury Versus Aggravation of Pre-existing Injury

The most critical issue raised in many injury and workers compensation claims is the determination of "cause." Determining "cause" and "type of causal relationship" is important from a legal perspective, as it is a factor in determining liability. However, interpretations of "cause" and related definitions are often confusing. The legal definitions, interpretations and standards for causation in workers' compensation adjudication vary from jurisdiction to jurisdiction. Furthermore, they are frequently confusing, self-contradictory and open to various (mis)interpretations, even within the same jurisdiction. Although you must always apply the definitions, interpretations and standards of the jurisdiction in which the case is filed or to be heard, the most commonly referenced resources for determining cause and causal relationship are the Federal Employees Compensation Act (FECA) and the Guides to the Evaluation of Permanent Impairment (4th and 5th editions, published by the American Medical Association). Many states have their own variations of these definitions and standards. Direct Causation: This term refers to situations where the injury or factors of employment result in the condition claimed, through a natural and unbroken sequence. Aggravation: If a pre-existing condition is worsened, either temporarily or permanently, by a work-related injury or car accident, that condition is said to be aggravated. Therefore an aggravation of a pre-existing condition must include a stimulus that worsens the status quo of a susceptible condition. Temporary aggravation implies that the "aggravation" is temporary or self-limited, causing only a transient increase in symptoms, without persistent effect. This is sometimes referred to as an "exacerbation" and usually involves a limited period of impairment and/or medical treatment, after which the worker returns to his or her previous medical status. Permanent aggravation occurs when an "aggravation" causes permanent changes in the natural course of an ongoing condition. A permanent aggravation alters the natural course of the preexisting condition, accelerating or worsening that condition, such that it will never return to the pre-injury state. It is generally accepted that the extent of permanent aggravation should be "material" in order to consider it of relevance. In fact, according to the AMA Guidelines (4th edition), an aggravation requires that the injury or aggravating factor causes a "worsening of a preexisting medical condition or infirmity in such a way that the degree of permanent impairment increased by more than 3 percent." Therefore, in assessing an aggravation of a pre-existent condition, it is essential that the natural history of the pre-existing disorder be taken into consideration. A pre-existing disorder may, in and of itself, worsen over time without any intervening stimulus. It is only if there is a permanent alteration in the natural course of the pre-existing disorder that an aggravation can be appropriately claimed. However, if symptoms are only transiently increased, but the natural history of the preexisting disorder is not permanently altered, this should be considered only an "exacerbation."

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