California Labor Code § 4663

Determinative passage · p.6Pursuant to Labor Code Section 4663, Defendant bears the burden of proving apportionment with substantial evidence. Under Escobedo v. Marshalls (2005) 70 CCC 604, such burden is met if apportionment is supported by substantial medical evidence that explains how and why nonindustrial factors caused a percentage of the applicant's permanent disability. A medical opinion based on materially inaccurate or unresolved historical facts is not substantial evidence. In Pan Pacific Printing Press, Inc. v. WCAB (Whitt) (2016) 81 CCC 744 (writ denied), the QME report could not be relied upon for conclusions dependent on the inaccurate history that applicant had no prior back symptoms. Specifically, in the case of Whitt, "the WCAB explained in its decision that Dr. Broderick's conclusion that Applicant suffered a specific injury on 1/4/2012 was not substantial evidence because it was based on an incorrect history of no prior back injury." Here, Defendant contends that the court erred in declining to apply a 10% non-industrial apportionment based upon the opinions of Dr. Bertoldi and Dr. Sones, which opine that 10% of Applicant's permanent disability should be apportioned to non-industrial factors.

Defendant failed to meet burden due to inconsistent applicant history and speculative medical opinions.

Determinative passage · p.6(Gatten) (2006) 145 Cal.App.4th 922, 927–928 [71 Cal.Comp.Cases 1687].) Instead, apportionment of permanent disability is “based on causation” and the “employer shall only be liable for the percentage of permanent disability directly caused by the injury arising out of and occurring in the course of employment.” (Lab. Code, §§ 4663(a) and 4664(a).) “The plain reading of ‘causation’ in this context is causation of the permanent disability.” (Escobedo v. Marshalls (Escobedo) (2005) 70 Cal.Comp.Cases 604, 611 (Appeals Board en banc).) Apportionment now includes pathology, asymptomatic prior conditions, and retroactive prophylactic work preclusions, provided there is substantial evidence establishing that these other factors have caused permanent disability. Pursuant to Escobedo, a physician's opinion must rely on reasonable medical probability, cannot be speculative, must rely on pertinent facts and/or an adequate examination and history, and must set forth the reasoning in support of its

The WCJ applied these statutes to uphold Dr. Sommer's apportionment opinion and reject vocational apportionment.

Determinative passage · p.8“Section 4663(c) not only prescribes what determinations a reporting physician must make with respect to apportionment, it also prescribes what standards the WCAB must use in deciding apportionment; that is, both a reporting physician and the WCAB must make determinations of what percentage of the permanent disability was directly caused by the industrial injury and what percentage was caused by other factors.” (Escobedo v. Marshalls (2005) (en banc) Cal.Comp.Cases 604, 607)

Both the reporting physician and the WCAB must determine the percentage of permanent disability caused by industrial injury versus other factors.

Determinative passage · p.13Section 4663 provides that “[a]pportionment of permanent disability shall be based on causation.” (Lab. Code, § 4663(a).) A doctor who prepares a report addressing the issue of permanent disability due to a claimed industrial injury must address the issue of causation of the permanent disability. (Lab. Code, § 4663(b).) Section 4663 requires that the doctor “make an apportionment determination by finding what approximate percentage of the permanent disability was caused by the direct result of injury arising out of and occurring in the course of employment and what approximate percentage of the permanent disability was caused by other factors both before and subsequent to the industrial injury, including prior industrial injuries.” (Lab. Code, § 4663(c).) Pursuant to section 4663(c) and section 5705, it is defendant that has the burden of establishing the approximate percentage of permanent disability caused by factors other than the industrial injury.

Dr. Greenberg addressed apportionment and found 100% industrial causation with no non-industrial contribution.

Determinative passage · p.13Cal.4th 1313, 1321 [72 Cal.Comp.Cases 565]; Marsh v. Workers’ Comp. Appeals Bd. (2005) 130 Cal.App.4th 906, 911 [70 Cal.Comp.Cases 787.].) The mere fact that a medical report assigns approximate percentages of industrial and nonindustrial causation does not make the report reliable medical evidence by itself. (E.L. Yeager Construction v. Workers' Comp. Appeals Bd. (Gatten) (2006) 145 Cal.App.4th 922, 927–928 [71 Cal.Comp.Cases 1687].) Instead, apportionment of permanent disability is “based on causation” and the “employer shall only be liable for the percentage of permanent disability directly caused by the injury arising out of and occurring in the course of employment.” (Lab. Code, §§ 4663(a) and 4664(a).) “The plain reading of ‘causation’ in this context is causation of the permanent disability.” (Escobedo v. Marshalls (Escobedo) (2005) 70 Cal.Comp.Cases 604, 611 (Appeals Board en banc).) Apportionment now includes pathology, asymptomatic prior conditions, and retroactive prophylactic work preclusions, provided there is substantial evidence establishing that these other factors have caused permanent disability. Pursuant to Escobedo, a physician's opinion must rely on reasonable medical probability, cannot be speculative, must rely on pertinent facts and/or an adequate examination and history, and must set forth the reasoning in support of its conclusions. (Id. at p.

The Board applied this standard to evaluate the apportionment evidence and burden of proof.

Determinative passage · p.8section 4663(e) exempts applicant’s low back injury from apportionment to causation that would otherwise be required under section 4663(a). However, section 4664(a) also provides that the employer is only liable for the percentage of permanent disability directly caused by the injury arising out of and occurring in the course of employment. Pursuant to section 4664(b), applicant’s prior low back disability is conclusively presumed to exist at the time of any subsequent industrial injury. Accordingly, the issue before us involves whether the anti-attribution provisions of section 4663(e), which preclude apportionment based on causation, would also preclude the apportionment required under section 4664(b) to applicant’s prior award of disability. In Bates, supra, 84 Cal.Comp.Cases 648, the WCJ found that applicant sustained two consecutive cumulative injuries, the first from May 10, 2009 to May 10, 2010, and another beginning May 10, 2010 through April 18, 2012. Both injuries were subject to the “heart trouble” presumptions of section 3212. The WCJ entered one award of disability for both injuries but allowed credit for the dollar value of the prior industrial award. (Id. at p. 650.) Defendant petitioned for reconsideration, contending that section 4664(a) and Benson v. Workers’ Comp.

Anti-attribution provisions of section 4663(e) do not preclude apportionment under section 4664(b) to prior awards.

Determinative passage · p.6Therefore, defendant carries the burden of proof on apportionment. (Lab. Code, § 5705.) Apportionment of permanent disability must address causation of disability and must constitute substantial evidence. (Escobedo, supra at pp. 611, 620-621.) To constitute substantial evidence “…a medical opinion must be framed in terms of reasonable medical probability, it must not be speculative, it must be based on pertinent facts and on an adequate examination and history, and it must set forth reasoning in support of its conclusions.” (Id. at 621.) Causation of disability is not to be confused with causation of injury. (Id. at 611.) Dr. Feingold’s apportionment opinions do not constitute substantial evidence because he does not address the causation of applicant’s disability, instead Dr. Feingold apportioned the applicant’s “impairment.” Evaluating physicians determine the extent of an applicant’s impairment using the AMA Guides, this is a medical determination. Then, the assigned impairment is rated or adjusted for the applicant’s diminished future earning capacity, occupation and age at the time of injury resulting in a level of permanent disability, this is a non-medical determination to account for an applicant’s inability to compete in the open labor market. (Lab.

The WCAB rejected Dr. Feingold's apportionment opinions because he apportioned impairment rather than disability and failed to explain causation of disability, thus no legal basis for apportionment was found.

Determinative passage · p.10(Gatten) (2006) 145 Cal.App.4th 922, 927–928 [71 Cal.Comp.Cases 1687].) Instead, apportionment of permanent disability is “based on causation” and the “employer shall only be liable for the percentage of permanent disability directly caused by the injury arising out of and occurring in the course of employment.” (Lab. Code, §§ 4663(a) and 4664(a).) “The plain reading of ‘causation’ in this context is causation of the permanent disability.” (Escobedo v. Marshalls (Escobedo) (2005) 70 Cal.Comp.Cases 604, 611 (Appeals Board en banc).) Apportionment now includes pathology, asymptomatic prior conditions, and retroactive prophylactic work preclusions, provided there is substantial evidence establishing that these other factors have caused permanent disability.

Employer liable only for PD directly caused by industrial injury; apportionment includes pathology and prior conditions with substantial evidence.