Can a Finding of a “Synergistic Effect” Allow the Use of a Different Method Than the Combined Value Chart (CVC) to Combine Impairments?

CVC: The “Traditional” Method.

In general, when you are injured, you will be given an impairment rating by a doctor for that injured body part, which determines the amount of disability benefits you get depending on your impairment rating. The ratings for injuries are expressed as a percentage from 0% (no disability) to 100% (permanent total disability). In situations where you have multiple body parts or systems involved in a separate injury, the values of each rating are combined in order to not exceed a total rating of 100%. The preferred approach that is used to combine multiple impairments is to use a formula from the Combined Values Chart (CVC). An example of combining a rating of 15% and 25% using the CVC results in a combined rating of 36%. Schedule for Rating Permanent Disabilities, DIR (January 2005), https://www.dir.ca.gov/dwc/pdr.pdf.

What is a “Synergistic Effect”?

The term “synergistic effect” comes from the Kite case, although Kite does not actually define the term itself. Kite seems to suggest a “synergistic effect” is found when one body part or system is unable to compensate for another body part or system when injured. In Kite, the applicant sustained injuries to both sides of their hip, and so neither hip could compensate for the other, and thus a “synergistic effect” was found. Athens Administrators v. Workers’ Comp. Appeals Bd. (Kite), 78 Cal. Comp. Cases 213 (Cal. App. 1st Dist. February 28, 2013).
The case of Brian provided a definition for the term “synergy”, which is the interaction or cooperation of two or more systems that produce a combined effect greater than the sum of their separate effects. Brian seems to suggest then that a “synergistic effect” occurs when two or more impairments influence each other simultaneously, causing some effect, like pain, to be greater than if the impairments caused it on their own. In Brian, the doctor found a “synergistic effect” when applicant’s cognitive and psychological impairments influenced each other to cause greater harm than if they were considered individually, and that both symptoms did not overlap. Hodson (Brian) v. Vacasa, LLC, 86 Cal. Comp. Cases 1049 (Cal. Workers’ Comp. App. Bd. July 8, 2021).

What Happens Upon Finding a “Synergistic Effect”?

Once a Qualified Medical Examiner (QME) finds a “synergistic effect” between two or more impairments, the QME can suggest an alternative method to combine the impairment ratings, as long as the method provides a more accurate depiction of the overall impairment than the CVC method. The most commonly used alternative method when finding a “synergistic effect” is simple addition. Thus, adding an impairment rating of 15% and 25% as shown before would result in a rating of 40%, as opposed to the 36% under the CVC.
But it still must be cautioned that a finding of a “synergistic effect” and whether to use an alternative method to the CVC is a medical decision. It is up to the medical evaluator whether or not to apply Kite, as the method used must be the most accurate reflection of an applicant’s permanent disability. Athens Administrators v. Workers’ Comp. Appeals Bd. (Kite), 78 Cal. Comp. Cases 213. As the court in Kite noted, “A scientific formula has not been established to indicate the best way to combine multiple impairments. Given the diversity of impairments and great variability inherent in combining multiple impairments, it is difficult to establish a formula that accounts for all situations…[Thus] [m]any workers’ compensation statutes contain provisions that combine impairments to produce a summary rating that is more than additive. Other options are to combine (add, subtract, or multiply) multiple impairments based upon the extent to which they affect an individual’s ability to perform activities of daily living.” Id.