Opinion
NOT TO BE PUBLISHED
WCAB No. SAC0323238
HULL, J.Lois Vaira (petitioner) filed a petition for writ of review from an order of the Workers’ Compensation Appeals Board (WCAB) upholding a decision awarding her permanent disability benefits for a spinal injury. We granted the petition.
Petitioner contends the WCAB erred in apportioning a share of her disability to her age and a pre-existing condition of osteoporosis. She further contends the WCAB erred in reducing the overall award based on an earlier injury for which she had been awarded permanent disability benefits.
We conclude the WCAB’s specific apportionment to age and osteoporosis is not supported by substantial evidence. We further conclude any apportionment to age, per se, runs afoul of state antidiscrimination law. We annul the order of the WCAB and remand the matter for further proceedings.
FACTS AND PROCEEDINGS
On January 27, 2003, while working as a receptionist for respondent California Travel and Tourism Commission (CTTC), petitioner hurt her back when she bent over to pick up some travel brochures that had fallen off a shelf. At the time, CTTC was insured for purposes of workers’ compensation by respondent State Compensation Insurance Fund (SCIF).
Petitioner was 73 years old at the time of the injury. Five months earlier, on August 14, 2002, petitioner had suffered another work-related injury and filed a separate workers’ compensation claim (WCAB No. SAC0323237).
An agreed medical examiner, Dr. Blaine Johnson, examined petitioner on May 23, 2005. He concluded plaintiff suffered a compression fracture at T12 on her spinal column and had become permanent and stationary by February 2004. He further concluded petitioner’s age and a preexisting osteopenia or osteoporosis of her spinal column contributed to her disability. Dr. Johnson apportioned 40 percent of petitioner’s disability to her preexisting conditions and 60 percent to the industrial injury.
The parties stipulated to overall disability of 64 percent after adjustment for age and occupation but before apportionment.
On May 19, 2006, the workers’ compensation judge (WCJ) issued his initial findings and award. He accepted the parties’ stipulation of 64 percent permanent disability and adopted Dr. Johnson’s apportionment of 40 percent to preexisting conditions. Petitioner was awarded $51,152.50 in permanent disability benefits.
Petitioner filed a petition for reconsideration, and the WCJ rescinded his findings and award and sent the matter to a disability evaluator.
On August 15, 2006, the WCJ issued a revised award. He again found 64 percent permanent disability pursuant to the parties’ stipulation. However, he also found overlapping disability from the August 14, 2002, injury, and reduced the overall disability for the current injury to 54 percent. The WCJ again apportioned 40 percent of the resulting disability to petitioner’s age and preexisting osteoporosis. She was awarded $40,283.75 in permanent disability benefits.
Petitioner again sought reconsideration, and the WCJ again rescinded his findings and award.
On November 3, 2006, the WCJ issued his third findings and award, again finding 54 percent disability after reduction for overlapping disability and 40 percent apportionment to preexisting conditions. However, the WCJ deferred final calculation of the monetary award pending legislative or judicial determination of the proper method for doing so.
Petitioner once again sought reconsideration. However, this time, the WCJ issued a report and recommendations against reconsideration. The WCAB adopted the WCJ’s recommendations and denied reconsideration.
DISCUSSION
I
Introduction
Petitioner contends the WCAB erred in apportioning part of her disability to her age and osteoporosis and in reducing her overall percentage of permanent disability based on a prior award. As we shall explain, we agree with petitioner in part.
“In reviewing an order, decision, or award of the WCAB, an appellate court must determine whether, in view of the entire record, substantial evidence supports the WCAB’s findings.” (Gee v. Workers’ Comp. Appeals Bd. (2002) 96 Cal.App.4th 1418, 1423-1424.) “This court may not reweigh the evidence or decide disputed questions of fact. [Citations.] However, this court is not bound to accept the WCAB’s factual findings if determined to be unreasonable, illogical, improbable or inequitable when viewed in light of the overall statutory scheme.” (Western Growers Ins. Co. v. Workers’ Comp. Appeals Bd. (1993) 16 Cal.App.4th 227, 233.)
One of the many benefits available to an injured worker is compensation for permanent disability. “‘[P]ermanent disability is understood as “the irreversible residual of an injury.”’ [Citation.] ‘A permanent disability is one “. . . which causes impairment of earning capacity, impairment of the normal use of a member, or a competitive handicap in the open labor market.”’ [Citation.] Thus, permanent disability payments are intended to compensate workers for both physical loss and the loss of some or all of their future earning capacity.” (Brodie v. Workers’ Comp. Appeals Bd. (2007) 40 Cal.4th 1313, 1320 (Brodie).)
“Employers must compensate injured workers only for that portion of their permanent disability attributable to a current industrial injury, not for that portion attributable to previous injuries or to nonindustrial factors. ‘Apportionment is the process employed . . . to segregate the residuals of an industrial injury from those attributable to other industrial injuries, or to nonindustrial factors, in order to fairly allocate the legal responsibility.’” (Brodie, supra, 40 Cal.4th at p. 1321.)
II
Lighting Up of Preexisting Conditions
Petitioner contends there can be no apportionment of disability based on her age and osteoporosis. She argues the law on apportionment has long recognized that an employer takes the employee as it finds her and a “‘lighting up,’ acceleration or aggravation of a preexisting condition is not a valid basis for apportionment.” Petitioner further argues recent amendments to the apportionment statutes have not changed the law in this regard.
Prior to 2004, Labor Code section 4663 read: “In case of aggravation of any disease existing prior to a compensable injury, compensation shall be allowed only for the proportion of the disability due to the aggravation of such prior disease which is reasonably attributable to the injury.” (Stats. 1937, ch. 90, § 4663, p. 284; further undesignated section references are to the Labor Code.) Former section 4750 read: “An employee who is suffering from a previous permanent disability or physical impairment and sustains permanent injury thereafter shall not receive from the employer compensation for the later injury in excess of the compensation allowed for such injury when considered by itself and not in conjunction with or in relation to the previous disability or impairment. [¶] The employer shall not be liable for compensation to such an employee for the combined disability, but only for that portion due to the later injury as though no prior disability or impairment had existed.” (Stats. 1945, ch. 1161, § 1, p. 2209.)
Under the foregoing provisions, the WCAB was required to “allow compensation not only for the disability resulting solely from the employment, but also for that which results from the acceleration, aggravation, or ‘lighting up’ of a prior nondisabling disease. Apportionment [was] justified only if the Board [found] that part of the disability would have resulted from the normal progress of the underlying nonindustrial disease.” (Pullman Kellogg v. Workers’ Comp. Appeals Bd. (1980) 26 Cal.3d 450, 454.)
For example, in Pullman Kellogg v. Workers’ Comp. Appeals Bd., supra, 26 Cal.3d 450, the employee suffered a permanent disability caused by lung disease. A medical expert opined that 50 percent of the employee’s lung disease was caused by industrial exposure to harmful substances and 50 percent to smoking. The Supreme Court concluded no apportionment was permitted, because “[i]t is disability resulting from, rather than a cause of, a disease which is the proper subject of apportionment; ‘pathology’ may not be apportioned.” (Id. at p. 454.) Under former section 4663, apportionment required a showing that the apportioned percentage of permanent disability would have resulted even in the absence of the industrial injury. (Ditler v. Workers’ Comp. Appeals Bd. (1982) 131 Cal.App.3d 803, 811-812; Gay v. Workers’ Comp. Appeals Bd. (1979) 96 Cal.App.3d 555, 562.)
In 2004, the Legislature enacted Senate Bill No. 899 (2003-2004 Reg. Sess.) (Senate Bill 899), repealing section 4750 (Stats. 2004, ch. 34, § 37) and rewriting section 4663 (id., at §§ 33-34) to read:
“(a) Apportionment of permanent disability shall be based on causation.
“(b) Any physician who prepares a report addressing the issue of permanent disability due to a claimed industrial injury shall in that report address the issue of causation of the permanent disability.
“(c) In order for a physician’s report to be considered complete on the issue of permanent disability, the report must include an apportionment determination. A physician shall 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. . . .”
Senate Bill 899 also added section 4664 (Stats. 2004, ch. 34, § 35). Subdivision (a) of that section reads: “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.” These legislative changes apply to all proceedings not yet final at the time of their enactment. (E & J Gallo Winery v. Workers’ Comp. Appeals Bd. (2005) 134 Cal.App.4th 1536, 1543, disapproved on other grounds in Brodie, supra, 40 Cal.4th at p. 1332.)
Petitioner contends Senate Bill 899 did not change the law prohibiting apportionment where an industrial injury accelerates, aggravates, or “lights up” a prior nondisabling condition. According to petitioner, the industrial injury is still the cause of such disability, unless it can be shown that part of the disability would have resulted from the natural progression of the preexisting condition.
CTTC and SCIF (respondents) do not contend otherwise. In their answer to the petition for writ of review, respondents adopt the reasoning of the WCJ in his report and recommendation on petition for reconsideration. In that report, the WCJ acknowledged pre-Senate Bill 899 law that apportionment to a preexisting condition is permitted only if disability would have resulted from the natural progression of that condition. However, rather than assert a change in that law, the WCJ merely described the statutory changes and cited Escobedo v. Marshalls (2005) 70 Cal.Comp.Cases 604 (Escobedo). In Escobedo, the WCAB upheld an apportionment of 50 percent of the petitioner’s permanent disability to a preexisting arthritic condition in her knee despite the fact she had been asymptomatic prior to her industrial injury. According to the WCJ, “[t]he identical situation herein exists; that an underlying pathology contributed to the cause of disability and whether lighted up or not, substantial evidence exists to justify the apportionment.”
Escobedo does not support a finding that the law of apportionment changed with Senate Bill 899. In that case, the WCAB did not conclude that apportionment to an underlying pathology is permitted even where that pathology is “lighted up” by an industrial injury. Rather, in concluding substantial evidence supported the 50 percent allocation to the preexisting arthritic condition, the WCAB relied on the opinion of the defendant’s qualified medical evaluator (QME). The QME opined that “‘it is medically probable that she would have had fifty percent of her current level of knee disability at the time of today’s evaluation even in the absence of her employment . . . .” (Escobedo, supra, 70 Cal.Comp.Cases at p. 608.) In other words, 50 percent of the disability would have resulted from the natural progression of the employee’s arthritis. Thus, in Escobedo, the WCAB did not apply a new standard for apportionment but concluded the old standard had been satisfied.
Nevertheless, following briefing in this matter, the state Supreme Court decided Brodie, supra, 40 Cal.4th 1313. In Brodie, the court discussed the effect of the recent amendments to the apportionment statutes. After first reciting the prior rules of apportionment, including that prohibiting apportionment to a preexisting condition unless disability would have occurred from the normal progression of that condition, the court indicated Senate Bill 899 had effected a sea change. According to the high court: “The plain language of new sections 4663 and 4664 demonstrates they were intended to reverse these features of former sections 4663 and 4750. [Citation.] Thus, new sections 4663, subdivision (a) and 4664, subdivision (a) eliminate the bar against apportionment based on pathology and asymptomatic causes . . . .” (Brodie, supra, at p. 1327.) According to the court, prior law, as interpreted by the courts, was “inconsistent with the new regime of apportionment based on causation.” (Ibid.) The court continued: “Former section 4750 required consideration of the new injury ‘by itself and not in conjunction with or in relation to the previous disability or impairment’ and further called for compensation for the later injury to be determined ‘as though no prior disability or impairment had existed.’ But under Senate Bill No. 899 (2003-2004 Reg. Sess.), the new approach to apportionment is to look at the current disability and parcel out its causative sources--nonindustrial, prior industrial, current industrial--and decide the amount directly caused by the current industrial source. This approach requires thorough consideration of past injuries, not disregard of them.” (Id. at p. 1328.)
Under the current version of the apportionment statutes, which are applicable to this matter, apportionment to a prior condition that was lighted up, accelerated or aggravated by the current industrial injury is appropriate.
III
Allocation to Preexisting Conditions
Petitioner contends the record does not contain substantial evidence to support the WCAB’s apportionment of 40 percent of her disability to age and osteoporosis. In particular, she argues the WCAB relied on the opinion of Dr. Johnson, but Dr. Johnson confused causation of injury with causation of disability and only the latter is a valid basis for an apportionment. According to petitioner, the two factors mentioned by Dr. Johnson--age and osteoporosis--were contributing causes of her spinal injury, not her disability.
Respondents do not dispute that apportionment is only proper where a preexisting condition or prior injury contributes to the employee’s disability, rather than the employee’s injury. Thus, for purposes of review, they concede that if petitioner’s age and osteoporosis made her more susceptible to a spinal injury, and therefore were contributing causes of the January 27, 2003, injury, rather than contributing causes of petitioner’s permanent disability following that injury, no apportionment was permitted.
In its order denying reconsideration, the WCAB adopted and incorporated the report of the WCJ. The WCJ in turn relied almost exclusively on the opinion of Dr. Johnson, the agreed medical examiner. While acknowledging “it can be argued that apportionment to age and osteoporosis is related to an injury analysis rather than an apportionment of disability analysis,” the WCJ concluded Dr. Johnson, in both his report and deposition, focused not on injury but on disability apportionment. According to the WCJ: “Although [Dr. Johnson] does not quarrel with the characterization used by [petitioner’s] counsel that [petitioner’s] clearly existent pathology are ‘risk factors,’ there is no dispute in this record that [petitioner] possessed an age related condition in her spine known as osteoporosis. And there is no question in Dr. Johnson’s analysis that this age related condition caused a part of [petitioner’s] disability following the work injury.”
We agree with the WCAB that substantial evidence supports an apportionment of disability to preexisting conditions. As we shall explain, Dr. Johnson clearly opined that age and osteoporosis contributed to petitioner’s disability. However, the question here is not whether it was proper to apportion some disability to preexisting conditions but whether it was proper to apportion 40 percent of the disability to those conditions.
In the section of his report entitled “CAUSATION AND APPORTIONMENT,” Dr. Johnson begins: “With regard to causation and apportionment, it is my opinion that [petitioner] certainly does have risks secondary to the aging process and the preexisting osteopenia or osteoporosis of her spinal column. These two conditions lumped together would be responsible for 40% of her now current level of disability, and 60% would be due to her current injury, which resulted in the fracture of T12 while under the employ of [CTTC].” The foregoing suggests Dr. Johnson was focused on causation of disability rather than causation of injury. However, Dr. Johnson continued: “Certainly the osteoporosis predisposed her to the fracture. It also would tend to contribute to her now current level of pain.” This suggests Dr. Johnson recognized the preexisting conditions contributed both to the disability (increasing her level of pain) and to the injury (predisposing her to the T12 fracture).
In his deposition, Dr. Johnson similarly explained that the preexisting conditions made petitioner more susceptible to injury. In response to a question about how he arrived at a 40 percent apportionment, Dr. Johnson said: “[I]t was my opinion that, you know, her age predisposed her to the injury, the presence of osteoporosis, and possibly other factors of which, you know, in the physical examination may have shown up. You put those together, and it just seemed to me like she was pretty significantly at risk.” Although Dr. Johnson later explained the preexisting conditions were “keeping her from recovering at this point to a degree,” it is nevertheless clear his focus was on both causation of injury and causation of disability.
“Medical reports and opinions are not substantial evidence if they are known to be erroneous, or if they are based on facts no longer germane, on inadequate medical histories and examinations, or on incorrect legal theories. Medical opinion also fails to support the [WCAB]’s findings if it is based on surmise, speculation, conjecture, or guess.” (Hegglin v. Workmen’s Comp. Appeals Bd. (1971) 4 Cal.3d 162, 169.) A medical report will not be considered adequate to support an apportionment if it fails to refer to the proper standard but instead gives the inference that the medical expert relied on an improper standard. (See Dorman v. Workmen’s Comp. Appeals Bd. (1978) 78 Cal.App.3d 1009, 1018.)
On the present record, it is impossible to determine how much of the 40 percent of disability Dr. Johnson concluded was caused by preexisting conditions was based on the contribution of those conditions to her industrial injury rather than her industrial disability. It is not enough to say that Dr. Johnson’s opinion supports an apportionment to the preexisting conditions. The opinion must support the particular apportionment made.
We emphasize that respondents do not argue on review that recent statutory amendments have eliminated the distinction between causation of injury and causation of disability. We therefore presume for purposes of this case that such distinction still applies. The law on apportionment, as reflected in current sections 4663 and 4664, continues to concentrate on causation of disability.
The present record does not reveal whether Dr. Johnson, who was the agreed medical examiner, was asked to limit his apportionment to factors contributing solely to disability. The matter must therefore be remanded to the WCAB to take further evidence on this issue.
IV
Age and Gender Discrimination
Petitioner contends any reduction in disability benefits based on her age and osteoporosis amounts to both age and gender discrimination. Petitioner cites Government Code section 11135 (hereafter section 11135), subdivision (a), which reads: “No person in the State of California shall, on the basis of race, national origin, ethnic group identification, religion, age, sex, sexual orientation, color, or disability, be unlawfully denied full and equal access to the benefits of, or be unlawfully subjected to discrimination under, any program or activity that is conducted, operated, or administered by the state or by any state agency, is funded directly by the state, or receives any financial assistance from the state. . . .” Petitioner argues that while “[i]t is well known that risk factors for disease exists on the basis of race, ethnic group identification, age, sex and disability,” amended Labor Code section 4663 cannot be read to permit discrimination in the payment of disability benefits based on these factors.
The short answer to this contention is that in the preceding section we conclude the WCAB may not use risk factors of injury in apportioning disability. Although Dr. Johnson appears to have mixed causation of injury with causation of disability, we conclude the matter must be remanded to permit further evidence on how much of petitioner’s disability may be attributed to her preexisting conditions.
Amici The Impact Fund, AARP, American Civil Liberties Union of Northern California, Equal Rights Advocates, and Public Advocates (The Impact Fund) contend that apportionment of disability to age and osteoporosis, even where those factors contribute to disability rather than injury, violates section 11135. According to The Impact Fund, apportionment to age is per se unlawful and apportionment to osteoporosis is improper because it disproportionately impacts women. The Impact Fund argues: “Under the approach taken by the Board, awards could be reduced for other workers based on impermissible factors such as race, ethnicity or disability. Using the same logic approved by the WCAB, African-American workers could see their workers’ compensation awards reduced because they have sickle cell anemia or high blood pressure, conditions that affect African Americans disproportionately compared to Caucasian workers.”
Amicus California Workers’ Compensation Institute (CWCI) counters that section 11135 does not apply to the administration of workers compensation benefits, because the workers’ compensation program is not funded by the state and the state provides no financial assistance to beneficiaries. However, this argument ignores the language of the statute. It states that no person may be denied equal benefits of any program “that is conducted, operated, or administered by the state or by any state agency, is funded directly by the state, or receives any financial assistance from the state.” (§ 11135, subd. (a).) It is not necessary that the program be funded by the state or that the state provides financial benefits, so long as the program is conducted, operated, or administered by the state. CWCI does not contend the state workers’ compensation program is not conducted, operated, or administered by the state.
CWCI contends Dr. Johnson did not apportion disability based on any stereotype about age and gender but on the preexisting conditions of this particular claimant. CWCI further contends there is no evidence in this record to support a conclusion that apportionment based on osteoporosis has a disparate impact on women. We agree with CWCI in part.
The matter below was not litigated on a theory of disparate impact as applied to the apportionment of disability to osteoporosis. Hence, there is no evidence in the record to support a finding of disparate impact.
Furthermore, assuming such disparate impact exists, we disagree with The Impact Fund that this establishes a violation of section 11135. Reducing permanent disability benefits based on a preexisting condition that is a contributing factor of disability is not discrimination. When the WCAB determines a preexisting condition contributes to a given disability, and apportions accordingly, this is merely a recognition that a portion of the disability exists independent of the industrial injury. The injured worker is being compensated only for the disability caused by the industrial injury. To this extent, the injured worker is being treated no differently than an injured worker who does not suffer from the preexisting condition. Both would be compensated for the amount of disability caused by the industrial injury. This is no different than if the WCAB apportioned disability to a prior industrial injury. Such apportionment is not discrimination based on disability.
For example, in petitioner’s case, assuming Dr. Johnson had properly apportioned 40 percent of her disability to her osteoporosis, this would mean that 40 percent of her total disability of 54 percent, or 21.6 percent, was caused by osteoporosis. In other words, prior to the industrial injury, petitioner was already 21.6 percent disabled and only 32.4 percent of her disability was caused by the industrial injury. Petitioner would receive workers’ compensation benefits based on the 32.4 percent of disability caused by her employment.
The Impact Fund would have us compare petitioner to a male worker without osteoporosis who has an industrial injury resulting in 54 percent disability. The Impact Fund contends it is discriminatory to allow that male worker to receive benefits based on 54 percent disability but award petition benefits based on only 32.4 percent disability. However, this comparison is not apt. The male worker whose injury caused 54 percent disability has received a more severe injury than petitioner. The proper comparison is with a male worker whose injury caused 32.4 percent disability. All other things being equal, both petitioner and the male worker would receive the same benefits.
We emphasize that this case does not present a claim that the WCAB has apportioned disability to a condition peculiar to women while failing to give equal treatment to a condition peculiar to men that may also contribute to disability. Such unequal treatment of disabling conditions peculiar to a particular race, ethnicity or gender may give rise to a claim of discrimination.
Turning now to the issue of age, CWCI contends the WCAB did not actually apportion disability to age but only the osteoporosis arising from advancing age. However, this is belied by the conclusions and deposition testimony of Dr. Johnson, on which the WCAB relied. As noted earlier, Dr. Johnson stated: “With regard to causation and apportionment, it is my opinion that [petitioner] certainly does have risks secondary to the aging process and the preexisting osteopenia or osteoporosis of her spinal column. These two conditions lumped together would be responsible for 40% of her now current level of disability . . . .” Dr. Johnson further stated: “[I]t was my opinion that, you know, her age predisposed her to the injury, the presence of osteoporosis, and possibly other factors of which, you know, in the physical examination may have shown up.” Clearly, Dr. Johnson was focusing both on age and osteoporosis.
To the extent Dr. Johnson based his apportionment of 40 percent of disability on petitioner’s age, this would appear to violate section 11135. The WCAB may not reduce petitioner’s benefits simply because she is older than another similarly situated worker. However, on the record before us, we cannot determine if this is what Dr. Johnson did. It cannot reasonably be disputed that a correlation exists between ability to perform certain mental and physical tasks and age. Typically, a 60-year-old woman cannot lift as much as she could when she was 30. A 60-year-old man may not have the mental abilities he had when he was 30. On the other hand, a given 60-year-old may be just as strong or just as sharp mentally as another who is only 30 years old.
To the extent osteoporosis or some other physical or mental condition that might contribute to a work-related disability arises or becomes more acute with age, we see no problem with apportioning disability to that condition. However, in such case, apportionment is not to age but to the disabling condition. In this case, when Dr. Johnson mentioned petitioner’s age as a contributing factor of her disability, he may have been referring to the fact that her osteoporosis has become more acute with age. On the other hand, he may have been using the term “age” as a shorthand reference to the many other physical and mental conditions that tend to come with age.
On the present record, we cannot determine if Dr. Johnson, and hence the WCAB, apportioned disability to age per se rather than to one or more physical or mental conditions associated with age that contribute to her disability. The matter must therefore be remanded to the WCAB to take further evidence on this issue.
V
Reduction of Overall Disability for Prior Injury
Petitioner contends the WCAB erred in reducing her overall level of disability from 64 percent to 54 percent based on overlapping disability. She argues the parties had stipulated to an overall disability level of 64 percent and the WCAB’s reduction violated that stipulation. She further argues the parties did not request a determination on overlap. We find no error.
In her petition for reconsideration, petitioner challenged the reduction in overall disability. She argued: “Neither party requested the WCJ to address the issue of overlap. The issue for consideration was apportionment.”
Petitioner’s argument is one of semantics rather than substance. The summary of the evidence in this matter contains a number of stipulations, including the following: “The overall level of disability in SAC 323238, the 1/27/03 date of injury, is 64 percent after adjustment for age and occupation and not considering apportionment.” (Italics added.) In his final findings and award, the WCJ noted this stipulation and further found: “[Petitioner’s] overall permanent disability, after consideration of overlapping disability[,] is 54 percent.” In his report and recommendation on petition for reconsideration, the WCJ explained that, on November 3, 2006, petitioner had been awarded permanent disability in WCAB No. SAC0323237 (the August 14, 2002, injury) of 32 percent. The WCJ further explained the parties’ stipulation did not preclude an apportionment to the August 14 injury.
We agree with the WCAB that the parties’ stipulation did not preclude a reduction in the overall disability for the award in WCAB No. SAC0323237. As noted earlier, amended section 4663 requires physicians to make an “apportionment” by finding what portion of the disability was caused by the industrial injury and what portion “was caused by other factors both before and subsequent to the industrial injury, including prior industrial injuries.” (§ 4663, subd. (c), italics added.) Section 4664 states that an 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.” (§ 4664, subd. (a).) It further provides that “[i]f the applicant has received a prior award of permanent disability, it shall be conclusively presumed that the prior permanent disability exists at the time of any subsequent industrial injury.” (§ 4664, subd. (b).) Unless disability is total, the accumulation of all permanent disability awards for a particular region of the body cannot exceed 100 percent. (§ 4664, subd. (c).) These provisions effectively require an apportionment for any disability caused by a prior industrial injury.
In Kopping v. Workers’ Comp. Appeals Bd. (2006) 142 Cal.App.4th 1099, this court explained that apportionment concerns the allocation of disability among various causes whereas overlap is concerned with whether two or more injuries or conditions cause some or all of the same disability. We explained: “The conclusive presumption of section 4664[, subdivision] (b) is a presumption affecting the burden of proof because it affects the employer’s burden of proving apportionment by conclusively establishing that the permanent disability resulting from a previous industrial injury still existed at the time of the subsequent injury. Of course, under this reading of the statute, the employer would still have to prove that the previous disability, which was conclusively presumed to still exist, overlapped with the current disability.” (Kopping v. Workers’ Comp. Appeals Bd., supra, at p. 1107, italics added.)
When the parties stipulated to a particular level of disability before considering apportionment, they left open the possibility of apportioning some of the disability to a prior injury that caused an overlapping disability. Reservation of the issue of apportionment necessarily included any corresponding determination of overlap.
Petitioner also contends there is no evidence in the record to support a finding that the two injuries caused overlapping disabilities. However, this issue was not raised in petitioner’s petition for reconsideration. Therefore, it is forfeited for purposes of her petition for writ of review. (§ 5904; Employers Mut. Liab. Ins. Co. v. Workmen’s Comp. Appeals Bd. (1975) 46 Cal.App.3d 104, 109.)
DISPOSITION
The decision of the WCAB is annulled and the case is remanded for further proceedings consistent with the views expressed in this opinion.
We concur: DAVIS, Acting P.J., MORRISON, J.