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Special Report: WCAB Issues En Banc Decision Regarding Application of Kite

In 2013, the WCAB held in Athens Administrators v. WCAB (Kite) that an injured worker's disabilities are not required to be combined using the Combined Values Chart (CVC). The WCAB explained that although the AMA guides favor the combined values method, "physicians may, under certain circumstances, employ a different method of determining impairment if they remain within the four corners of the AMA Guides."

For more than 10 years, Kite became shorthand for combining disabilities by simple addition. Although the case is not binding, such addition is a common method accepted for combining an injured worker's disabilities. Over the years, many cases have applied Kite, but none of the cases was binding nor did any fully elaborate on the circumstances when disabilities could be combined by addition, rather than by using the CVC. The cases also largely depended on how well the physicians explained their opinions.

On June 10, 2024, in Vigil v. County of Kern, the WCAB issued an en banc decision holding that the CVC in the Schedule for Rating Permanent Disabilities (permanent disability ratings schedule, or PDRS) can be rebutted and impairments may be added when an applicant establishes the impact of each impairment on the activities of daily living (ADLs) and that either:

  1. There is no overlap between the effects on ADLs for the body parts rated. Or
  2. There is overlap, but it increases or amplifies the impact on the overlapping ADLs.


In Vigil, the applicant claimed two industrial injuries to his hips and back. He was evaluated by a qualified medical evaluator (QME), who assigned 15 percent whole person impairment (WPI) to the right hip, 15 percent WPI to the left hip and 7 percent WPI to the lumbar spine. At deposition, the QME testified that he was familiar with Kite, and believed it should be applied to the hips. He explained, "Somebody with limitations due to both hips is going to have significantly more limitations than if somebody had one normal hip and one hip that they had surgery on." The QME testified that it would be reasonable to add the disability for the hips, and the WCJ awarded permanent partial disability by adding the impairment to the applicant's left and right hip pursuant to Kite.


The WCAB noted that although the PDRS, which includes the CVC, is prima-facie evidence of the applicant's level of permanent disability, it is rebuttable. It explained that impairment under the AMA guides is designed to reflect how a disability affects a person’s activities of daily living, and that usually impairments to two or more body parts are expected to have an overlapping effect on the activities of daily living. So, under the AMA guides and the PDRS, the two impairments are combined to eliminate that overlap.

The WCAB explained that the first method for rebuttal of the CVC is to show that the multiple impairments have no overlap on the effects of the ADLs. It stated:

In determining whether the application of the CVC table has been rebutted in a case, an applicant must present evidence explaining what impact applicant’s impairments have had upon their ADLs. Where the medical evidence demonstrates that the impact upon the ADLs overlaps, without more, an applicant has not rebutted the CVC table. Where the medical evidence demonstrates that there is effectively an absence of overlap, the CVC table is rebutted, and it need not be used.

The WCAB explained the second method for rebutting the CVC was discussed first in Kite by showing the synergistic effect of two impairments on the applicant. It stated:

In some cases, two impairments overlap with one another in their effect on ADLs to the extent that they amplify one another to cause further impairment than what is anticipated in the AMA Guides. Thus, it is permissible to add impairments where a synergistic amplification of ADLs is shown.

It then stated:

The term ‘synergy’ is not a “magic word” that immediately rebuts the use of the CVC. Instead, a physician must set forth a reasoned analysis explaining how and why synergistic ADL overlap exists. If parties are searching for a magic word to use during a doctor’s deposition, that word is “Why?”. Rather than focusing on whether a specific term, including the term synergy, was used, it is imperative that parties focus on an analysis that applies critical thinking based on the principles articulated in Escobedo to support a conclusion based on the facts of the case. Such an analysis must include a detailed description of the impact of ADLs and how those ADLs interact.

The WCAB found that the QME provided little analysis for his conclusion that the applicant would have significantly more limitations after having both hips replaced. It noted that the QME's reporting contained no discussion of ADLs. So, the WCAB concluded that there was no substantial evidence to support a finding that the impairments should be added. It returned the matter to the WCJ to consider further development of the record under the principles outlined in the decision.


Vigil firmly entrenches Kite as a method for rebutting the PDRS. Although Kite was widely accepted and applied, Vigil, as an en banc decision, is binding on all appeals board panels and WCJs.

Vigil also thoroughly explains how the CVC can be rebutted to allow an applicant's impairments to be added. The applicant has the burden to establish the impact of each impairment on ADLs, and to establish that: (a) there is no overlap between the effects of ADLs between the body parts rated; or (b) there is overlap, but the overlap increases or amplifies the impact on the overlapping ADLs. That guidance had been applied in previous cases. So, Vigil doesn't establish new law. But it does clarify and summarize succinctly how the CVC can be rebutted.

Finally, Vigil emphasizes that rebuttal of the CVC is not based on any particular words. Applicants frequently sought to rebut the CVC by obtaining an evaluator's opinion regarding "synergistic effect" between different impairments. It has long been recognized, however, that a doctor's conclusions are not enough to constitute substantial evidence — he or she must disclose the underlying basis for the conclusions. So, although applicants can rebut the CVC by showing a synergistic effect between impairments, in such cases, doctors also must explain how and why synergism increases or amplifies the impact on the overlapping impairments.

Ultimately, Vigil doesn't make it any harder or easier for applicants to rebut the CVC. It simply provides guidance to practitioners on the evidence necessary to rebut. Moreover, even if the conditions for rebuttal of the CVC are present, the WCAB stated that the CVC "may be rebutted and impairments may be added ... (emphasis added)." So, a doctor is not required to apply Kite just because there is no overlap between the effects on ADLs, or there is an amplifying overlap. The doctor retains discretion to determine whether an applicant's permanent disability is more accurately reflected by the adding of impairments.

For further discussion of the CVC and its rebuttal, see Section 10.20 Combining Impairment and Disability.

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