Le Vesque v. Workmen's Comp. Appeals Bd. (1970) 1 Cal.3d 627, 637; Escobedo v. Marshalls (2005) 70 Cal.Comp.Cases 604, 620; E.L. Yeager Construction v. Workers' Comp. Appeals Bd. (Gatten) (2006) 145 Cal.App.4th 922, 928
Findings must be based on substantial evidence, which requires reasonable medical probability and a medical opinion with reasoning, not speculation or surmise.
The WCAB found that Dr. Agatstein's opinions lacked substantial evidence due to inadequate history and reasoning, requiring further development of the record.
From the decision · page 3All findings of the WCAB must be based on substantial evidence. (Le Vesque v.
Workmen's Comp. Appeals Bd. (1970) 1 Cal.3d 627, 637 [35 Cal.Comp.Cases 16]; Escobedo v.
Marshalls (2005) 70 Cal.Comp.Cases 604, 620 [Appeals Bd. en banc].) As the Court of Appeal
wrote in E.L. Yeager Construction v. Workers' Comp. Appeals Bd. (Gatten) (2006) 145
Cal.App.4th 922, 928 [71 Cal.Comp.Cases 1687], "In order to constitute substantial evidence, a
medical opinion must be predicated on reasonable medical probability. [Citation.] Also, a medical
opinion is not substantial evidence if it is based on facts no longer germane, on inadequate medical
histories or examinations, on incorrect legal theories, or on surmise, speculation, conjecture, or
guess. [Citation.] Further, a medical report is not substantial evidence unless it sets forth the
reasoning behind the physician's opinion, not merely his or her conclusions. [Citation.]"
Tyler v. Workers' Comp. Appeals Bd. (1997) 56 Cal.App.4th 389, 393-395; McClune v. Workers' Comp. Appeals Bd. (1998) 62 Cal.App.4th 1117, 1121-1122; Kuykendall v. Workers' Comp. Appeals Bd. (2000) 79 Cal.App.4th 396, 403
WCJ and Appeals Board have a duty to further develop the record when medical evidence is absent or insufficient, to ensure substantial justice.
The WCAB granted reconsideration and remanded for further development due to insufficient medical evidence on permanent disability and treatment.
From the decision · page 4The WCJ and the Appeals Board have a duty to further develop the record when there is a
complete absence of (Tyler v. Workers' Comp. Appeals Bd. (1997) 56 Cal.App.4th 389, 393-395
[62 Cal.Comp.Cases 924]) or even insufficient (McClune v. Workers' Comp. Appeals Bd. (1998)
62 Cal.App.4th 1117, 1121-1122 [63 Cal.Comp.Cases 261]) medical evidence on an issue. The
WCAB has a constitutional mandate to ensure "substantial justice in all cases." (Kuykendall v.
Workers' Comp. Appeals Bd. (2000) 79 Cal.App.4th 396, 403 [65 Cal.Comp.Cases 264].) Since,
in accordance with that mandate, "it is well established that the WCJ or the Board may not leave
undeveloped matters" within its acquired specialized knowledge (Id. at p. 404), pursuant to Labor
Code section 5906, we will grant reconsideration, rescind the WCJ's decision, and return this
matter to the trial level for further development of the record and decision on the issues of
permanent disability and further medical treatment. The parties and the WCJ should consider
whether this case is best served by an agreed medical evaluator or an independent medical
evaluator. Additionally, the applicant may require evaluation by other specialties. We express no
opinion on the ultimate resolution of this matter.