COLORADO COURT OF APPEALS                                          2017COA79


Court of Appeals No. 16CA1375
Industrial Claim Appeals Office of the State of Colorado
WC No. 4-972-492


Richard Hutchison,

Petitioner,

v.

Industrial Claim Appeals Office of the State of Colorado; Pine Country, Inc.,
d/b/a Pine Country Truck & Auto; and Pinnacol Assurance,

Respondents.


                              ORDER AFFIRMED

                                   Division II
                          Opinion by JUDGE DAILEY
                              Plank*, J., concurs
                          Berger, J., specially concurs

                           Announced June 1, 2017


Withers Seidman Rice & Mueller, P.C., David B. Mueller, Grand Junction,
Colorado, for Petitioner

No Appearance for Respondent Industrial Claim Appeals Office

Harvey Flewelling, Grant Butterfield, Denver, Colorado, for Respondents Pine
Country, Inc. and Pinnacol Assurance

William J. Macdonald, Aurora, Colorado, for Amicus Curiae Workers’
Compensation Education Association


*Sitting by assignment of the Chief Justice under provisions of Colo. Const. art.
VI, § 5(3), and § 24-51-1105, C.R.S. 2016.
¶1    In this workers’ compensation action, claimant, Richard

 Hutchison, challenges an order apportioning his benefits award. An

 administrative law judge (ALJ) determined that only one-third of

 claimant’s injury was work-related. The Industrial Claim Appeals

 Office (Panel) affirmed the ALJ’s decision. We conclude that

 claimant’s benefits award was properly apportioned and therefore

 affirm the Panel’s decision.

                                I. Background

¶2    Claimant works as a trailer mechanic for Pine Country, Inc.

 (employer). With the exception of a nine-month period in 1997,

 claimant has worked for employer since 1990. Claimant explained

 that his work required that “[y]ou get on your knees, pull the tires

 off or get on your knees to get underneath the trailer or crawl

 around on the trailer putting screws in the deck.” He estimated

 that he spends “half the time” on his knees while at work.

¶3    In 2012, claimant began experiencing right knee pain. He

 sought treatment from his personal physician, who referred him to

 an orthopedic specialist, Dr. Mitch Copeland, for further evaluation.

 Dr. Copeland diagnosed claimant with moderate to severe

 osteoarthritis of the right knee.


                                      1
¶4       In August 2012, claimant told Dr. Copeland that he also had

 pain in his left knee that was “intermittent and worsening” and

 occurred “without any known injury.” Claimant reported that this

 knee pain “began years ago, [but] worse[ned] in last 2 weeks.” Dr.

 Copeland diagnosed severe osteoarthritis in claimant’s left knee, as

 well.

¶5       Dr. Copeland injected Synvisc in both of claimant’s knees, but

 claimant did not experience much pain relief. Dr. Copeland also

 prescribed unloader braces for claimant’s knees.

¶6       In October 2014, when his symptoms worsened, claimant

 reported his knee pain to employer as a work-related occupational

 disease. Employer contested the claim on relatedness grounds. It

 bolstered its position with an independent medical examination

 conducted by Dr. J. Tashof Bernton. Dr. Bernton observed that

 claimant had “fairly diffuse osteoarthritis in many parts of his body.

 He is also overweight. These are independent predictors of

 osteoarthritis in the knee.” He opined that claimant’s work likely

 aggravated claimant’s arthritic knees, but suggested that claimant’s

 employment was not the cause of his arthritis:




                                     2
           While it is clearly evident to and beyond a
           reasonable degree of medical probability that,
           given his independent risk factors for knee
           osteoarthritis, the patient would have had
           osteoarthritis of the knees if he were not in his
           current job, the occupational history repeated
           lifting and squatting over years is sufficient to
           meet the standard in the Colorado Workers’
           Compensation Treatment Guidelines for
           aggravation of this condition on a work-related
           basis.

 He clarified that “to and beyond a reasonable degree of medical

 probability, the patient would have osteoarthritis of the knees

 whether or not he had his current job duties, although . . . those

 job duties aggravated the osteoarthritis.”

¶7    Claimant retained an independent physician to examine him.

 That doctor, Dr. John Hughes, recognized that claimant’s “weight,

 family history and idiopathic knee osteoarthritis are certainly

 independent risk factors for development of end stage osteoarthritis

 of the knees in a 55-year-old male.” He went on to note that “[a]s a

 result of this consideration, I cannot state within a reasonable

 degree of medical probability that knee pain is a direct and

 proximate result of work-related occupational stresses and strains

 due to [claimant’s] work as a mechanic for approximately 25 years.”

 Nevertheless, Dr. Hughes stated that he did “believe that work tasks


                                   3
 have substantially contributed to and worsened [claimant’s]

 bilateral knee osteoarthritis and other conditions. I believe his work

 is the proximate cause for his need for total knee arthroplasty

 [replacement] at this point in time.”

¶8    With conflicting reports, claimant applied for a hearing on the

 issue of compensability. At the hearing, Dr. Bernton reiterated his

 opinion that “beyond a reasonable degree of medical probability, the

 osteoarthritis would be there and the need for treatment with or

 without the occupational activity.” He also testified that claimant’s

 work “was not a necessary precondition” to his knee condition. As

 he did in his report, Dr. Bernton acknowledged that claimant’s work

 likely aggravated his knee condition, and he apportioned

 “approximately one-third” of claimant’s condition “to the

 occupational exacerbation.”

¶9    The ALJ found Dr. Bernton’s opinions credible and persuasive.

 The ALJ found that Dr. Bernton and Dr. Hughes “agree[d] that

 [c]laimant’s bilateral knee pain was not directly and proximately

 caused by [c]laimant’s work, but that the cause is multi-factorial in

 nature.” The ALJ credited Dr. Hughes’ and Dr. Bernton’s opinions

 that “independent risk factors” contributed to claimant’s knee


                                    4
  problems, specifically identifying claimant’s “weight, family history

  and idiopathic knee osteoarthritis.” The ALJ was also persuaded

  that claimant’s osteoarthritis “would more likely than not, have

  developed . . . regardless of whether or not claimant had a job or

  any occupational exposure.” The ALJ therefore adopted Dr.

  Bernton’s apportionment recommendation, attributing one-third of

  the cause of claimant’s bilateral knee osteoarthritis to work-related

  factors, and ordered employer to pay for “33.33 percent of all

  medical benefits and any compensation awarded in this claim as a

  result of [c]laimant’s work activities.”

¶ 10   On review, the Panel held that the ALJ had properly

  apportioned claimant’s benefits, and that the decision apportioning

  the benefits was supported by substantial evidence in the record.

  Claimant now appeals.

         II. Apportionment Under Section 8-42-104, C.R.S. 2016

¶ 11   Claimant contends that his knee condition arose from

  repetitive kneeling and crawling necessitated by his work as a

  trailer mechanic, rather than from a specific incident. He therefore

  sought coverage for an occupational disease, which is defined as:




                                      5
           “Occupational disease” means a disease which
           results directly from the employment or the
           conditions under which work was performed,
           which can be seen to have followed as a
           natural incident of the work and as a result of
           the exposure occasioned by the nature of the
           employment, and which can be fairly traced to
           the employment as a proximate cause and
           which does not come from a hazard to which
           the worker would have been equally exposed
           outside of the employment.

§ 8-40-201(14), C.R.S. 2016. “An occupational disease is present if

employment conditions act upon an employee’s pre-existing

weakness or hypersensitivity so as to produce a disabling condition

which would not have existed absent the employment conditions.”

Masdin v. Gardner-Denver-Cooper Indus., Inc., 689 P.2d 714, 717

(Colo. App. 1984). Masdin recognized that occupational diseases

may have both work-related and non-work-related causes, and that

an employer may therefore be liable for only a portion of a

claimant’s occupational disease. Id. Masdin apportionment was

adopted by the supreme court in Anderson v. Brinkhoff, 859 P.2d

819, 825 (Colo. 1993) (“We agree with the court of appeals in

Masdin[.]”).1


1 We note that the Workers’ Compensation Education Association
(WCEA) has submitted an amicus brief in this case primarily

                                  6
¶ 12   After Anderson, the legislature amended the apportionment

  statute to prohibit apportionment in certain circumstances. The

  current version of the statute — which was in effect when claimant

  filed his claim for coverage of his knee condition — provides: “An

  employee’s temporary total disability, temporary partial disability,

  or medical benefits shall not be reduced based on a previous

  injury.” § 8-42-104(3).2

¶ 13   The question we must answer, then, is whether claimant

  suffered a “previous injury” as that term is used in subsection (3).

  If so, then the statute would prohibit a reduction or apportionment



  arguing that Anderson misinterpreted the definition of
  “occupational disease.” However, because WCEA raises arguments
  that are not addressed by either party, we will not consider WCEA’s
  contentions. See Beaver Creek Prop. Owners Ass’n v. Bachelor
  Gulch Metro. Dist., 271 P.3d 578, 585 (Colo. App. 2011) (refusing to
  consider argument raised by amicus curiae that was not asserted
  by parties); SZL, Inc. v. Indus. Claim Appeals Office, 254 P.3d 1180,
  1189 (Colo. App. 2011) (refusing to consider “extensive additional
  issues” raised by amicus curiae “because only the issues raised by
  the parties are properly before us”).

  2  Section 8-42-104(4), C.R.S. 2016, expressly permits “reductions
  in recovery or apportionments allowed pursuant to the Colorado
  supreme court’s decision in the case denominated Anderson v.
  Brinkhoff, 859 P.2d 819 (Colo. 1993).” However, that subsection
  applies exclusively to claims for “permanent total disability.”
  Because claimant was seeking medical benefits only, subsection (4)
  is not at issue here.

                                    7
  of his medical benefits award “based on a previous injury.” The

  Panel concluded, however, that claimant had not suffered a

  previous injury and that section 8-42-104(3)’s prohibition therefore

  did not apply.

¶ 14   Claimant contends that the Panel erred in applying Anderson

  apportionment to his claim. He argues that the express terms of

  section 8-42-104(3) prohibit apportionment here. In addition, he

  challenges the ALJ’s application of Anderson apportionment to his

  claim, arguing that Anderson is distinguishable and apportionment

  under it is consequently unavailable. Specifically, he notes that

  unlike the claimant in Anderson, his knee condition was not

  “independently disabling before the industrial aggravation.” We

  conclude that apportionment was proper in this case.

           A. The Statute Does Not Prohibit All Apportionment

¶ 15   Whether section 8-42-104(3) prohibits apportionment is a

  matter of statutory interpretation, which we review de novo. See

  Ray v. Indus. Claim Appeals Office, 124 P.3d 891, 893 (Colo. App.

  2005), aff’d, 145 P.3d 661 (Colo. 2006).

¶ 16   Section 8-42-104 does not define “previous injury.” The

  general definitions of the Workers’ Compensation Act of Colorado


                                    8
  (Act) broadly define “injury” to “include[] disability or death

  resulting from accident or occupational disease.” § 8-40-201(2).

  This definition has remained unchanged since the Act’s

  reenactment in 1990. “Previous” is not defined in the Act, but its

  dictionary definition is “going before in time or order,” “prior to,

  before,” Webster’s Ninth New Collegiate Dictionary 933 (1989), or

  “going or existing before in time,” Webster’s Third New International

  Dictionary 1798 (2002).

¶ 17   “When we interpret a provision of the . . . Act, we give it its

  ‘plain and ordinary meaning’ if its language is clear.” Keel v. Indus.

  Claim Appeals Office, 2016 COA 8, ¶ 30 (quoting Davison v. Indus.

  Claim Appeals Office, 84 P.3d 1023, 1029 (Colo. 2004)). Injury is

  defined by the Act and “previous” has one clear dictionary

  definition. The phrase “previous injury” is consequently

  unambiguous: it means an accident causing injury or an

  occupational disease that occurred earlier in time to the claimant’s

  claim.

¶ 18   In reaching its decision, the Panel implicitly applied the plain,

  ordinary meaning of “previous injury.” The Panel noted that the

  occupational disease at issue here was “characterized as the


                                      9
  aggravation of osteoarthritis.” In other words, because the

  claimant’s knee condition was one ongoing disease with many

  causes, both work- and non-work- related, there was no separate

  “previous injury” as anticipated by section 8-42-104(3); it was

  instead one “injury” with multiple causes and not a “previous

  injury” because there was no onset of the occupational disease that

  occurred “before in time.” The Panel therefore concluded that

  section 8-42-104(3)’s prohibition against apportionment for a

  “previous injury” did not apply.

¶ 19   We discern no error in the Panel’s application of the definition

  of “previous injury.” Cf. Support, Inc. v. Indus. Claim Appeals Office,

  968 P.2d 174, 175 (Colo. App. 1998) (The Panel’s interpretation will

  be set aside only “if it is inconsistent with the clear language of the

  statute or with the legislative intent.”). Accordingly, neither the ALJ

  nor the Panel erred by concluding that section 8-42-104(3) did not

  prohibit apportionment in this case.

              B. ALJ and Panel Did Not Misapply Anderson

¶ 20   Claimant next contends that apportioning his injury was

  improper because his knee condition was not disabling until his

  work aggravated it. He argues that his situation is distinguishable


                                     10
  from Anderson because, in Anderson, the claimant’s condition

  manifested itself before work aggravated it. Specifically, he argues

  that unlike the claimant in Anderson, his occupational disease “was

  never independently disabling absent the job stressors.”

¶ 21   In Anderson, a carpenter who was exposed to sawdust on

  jobsites for approximately fifteen years sought workers’

  compensation coverage for his disabling emphysema alleging that

  the sawdust exposure caused his disease. Evidence showed,

  though, that the carpenter had “a hereditary condition which

  causes progressive emphysema and associated heart problems.”

  Anderson, 859 P.2d at 820. The carpenter also smoked cigarettes,

  “which further contributed to the progression of his disease.” Id.

  An ALJ concluded that the disabled carpenter’s “smoking and

  occupational dust exposures were co-equal aggravating factors in

  the acceleration of [his] severe emphysema.” Id. at 821 (alteration

  in original). The supreme court upheld the ALJ’s apportionment.

  Citing to Masdin, it held that “where there is no evidence that

  occupational exposure to a hazard is a necessary precondition to

  development of the disease, the claimant suffers from an




                                   11
  occupational disease only to the extent that the occupational

  exposure contributed to the disability.” Anderson, 859 P.2d at 825.

¶ 22   Contrary to claimant’s underlying presumption, Anderson does

  not require prior symptomology or limit apportionment to those

  injuries or illnesses that manifest themselves before a work-related

  exposure. True, the claimant in Anderson appears to have

  experienced symptoms before he began working for the employer

  and therefore was not asymptomatic. Id. at 820. But, Anderson’s

  reliance on and adoption of the holding in Masdin confirms that the

  timing of a claimant’s symptomology is not dispositive. Unlike the

  claimant in Anderson, the Masdin claimant “experienced a sudden

  episode of acute respiratory distress” while at work. Masdin, 689

  P.2d at 716. Nothing in that opinion suggests that the worker in

  Masdin experienced any symptoms of his disease before the

  “sudden” onset at work. Thus, the factual distinction between

  Anderson and claimant that he identifies does not render Anderson

  inapposite. We therefore reject claimant’s assertion that

  apportionment here was improper because his injury arose “in

  concert with and in tandem with other ‘risk factors.’”




                                   12
¶ 23   We also reject claimant’s assertion that Anderson prohibits

  ALJs from assigning any value to “genetic predisposition.”

  Claimant argues that Anderson attributed fifty percent of the

  carpenter’s emphysema to non-work-related smoking and fifty

  percent to his work-related sawdust exposure, but it did not

  apportion any of the claimant’s illness to his genetic predisposition.

  Anderson, 859 P.2d at 821. He points to this as effectively a

  prohibition against assigning any apportionment to a predisposition

  or latent genetic make-up, arguing that the ALJ’s apportionment of

  one-third of the cause of his knee condition to work-related

  aggravation and two-thirds to independent risk factors, including

  claimant’s “weight, family history and idiopathic knee

  osteoarthritis,” was improper and violated Anderson.

¶ 24   Essentially, claimant is arguing that employer was required to

  “take him as it finds him.” But, this is a tort concept that does not

  perfectly translate to workers’ compensation. See Schafer v.

  Hoffman, 831 P.2d 897, 900 (Colo. 1992) (“The negligent defendant

  is liable for the resulting harm even though the harm is increased

  by the particular plaintiff’s condition at the time of the negligent

  conduct.” (citing Prosser and Keaton on the Law of Torts § 43, at


                                     13
  291 (5th ed. 1984))); see also Restatement (Second) of Torts § 461

  cmt. a (Am. Law Inst. 1965) (“A negligent actor must bear the risk

  that his liability will be increased by reason of the actual physical

  condition of the other toward whom his act is negligent.”). Workers’

  compensation, however, does not incorporate the notion of fault or

  negligence. Employers are liable for work-related injuries to their

  employees regardless of fault. See § 8-41-301(1), C.R.S. 2016.

¶ 25   Certainly, the ALJ in Anderson did not apportion any of the

  claimant’s emphysema to his hereditary condition — he only

  apportioned claimant’s smoking and work conditions as causes —

  but Anderson does not expressly prohibit apportionment of a

  genetic condition. And, even though Anderson did not apportion

  any of the cause of claimant’s emphysema to his hereditary

  condition, other cases have reduced the employer’s liability for an

  injury based on a pre-existing condition. Most notably, in Duncan

  v. Industrial Claim Appeals Office, 107 P.3d 999 (Colo. App. 2004), a

  division of this court rejected a claimant’s contention that

  “apportionment of liability attributable to the natural aging process”

  was impermissible. Id. at 1001. The court instead held that “the

  fact that aging is a factor does not preclude apportionment.” Id.


                                    14
¶ 26   Claimant has cited to no authority that expressly precludes

  apportioning a claimant’s pre-existing genetic condition or natural

  proclivities. And, as shown by Duncan, other divisions have in fact

  upheld the very type of apportionment claimant challenges. We

  therefore perceive no error in the ALJ’s apportionment of two-thirds

  of claimant’s condition to “independent factors,” including his

  weight, family history, and pre-existing osteoarthritis.

            III. Substantial Evidence Supports ALJ’s Findings

¶ 27   Having concluded that neither the ALJ nor the Panel violated

  the Act or Anderson by apportioning claimant’s condition, we turn

  to claimant’s contention that substantial evidence does not support

  the ALJ’s finding apportioning only one-third of the liability for his

  injury to employer. He argues that this apportionment was based

  on speculation and was “violative of the apportionment principles.”

  We disagree.

¶ 28   In general, we will uphold an ALJ’s apportionment decision if

  it is supported by substantial evidence in the record. In reviewing

  Duncan and Anderson, it rapidly becomes clear that common to

  both opinions is the upholding of the ALJ’s apportionment decision

  because each decision was supported by substantial evidence in the


                                    15
  record. Anderson, 859 P.2d at 825 (“Because this percentage is

  supported by the evidence, Anderson is entitled to an award based

  upon it.”); Duncan, 107 P.3d at 1002 (upholding ALJ’s

  apportionment of seventy-five percent of claimant’s knee condition

  to pre-existing degenerative joint disease even though claimant’s

  knee had been asymptomatic before the work aggravation “[i]n light

  of the medical opinion that claimant would need a right knee

  replacement”); see also Res. One, LLC v. Indus. Claim Appeals Office,

  148 P.3d 287, 287-88 (Colo. App. 2006) (upholding an ALJ’s refusal

  to apportion the claimant’s pre-existing spinal condition and

  rejecting the employer’s assertion that it was entitled to

  apportionment as a matter of law).

¶ 29   “Substantial evidence is that quantum of probative evidence

  which a rational fact-finder would accept as adequate to support a

  conclusion, without regard to the existence of conflicting evidence.”

  Metro Moving & Storage Co. v. Gussert, 914 P.2d 411, 414 (Colo.

  App. 1995). “When an ALJ’s findings of fact are supported by

  substantial evidence, we are bound by them.” Paint Connection Plus

  v. Indus. Claim Appeals Office, 240 P.3d 429, 431 (Colo. App. 2010);

  see § 8-43-308, C.R.S. 2016.


                                    16
¶ 30   “We must also defer to the ALJ’s credibility determinations

  and resolution of conflicts in the evidence, including the medical

  evidence.” City of Loveland Police Dep’t v. Indus. Claim Appeals

  Office, 141 P.3d 943, 950 (Colo. App. 2006). The weight to be given

  to the experts’ testimony in this case “is a matter exclusively within

  the discretion of the [ALJ] as fact-finder.” Rockwell Int’l v. Turnbull,

  802 P.2d 1182, 1183 (Colo. App. 1990). “Further, we may not

  interfere with the ALJ’s credibility determinations except in the

  extreme circumstance where the evidence credited is so

  overwhelmingly rebutted by hard, certain evidence that the ALJ

  would err as a matter of law in crediting it.” Arenas v. Indus. Claim

  Appeals Office, 8 P.3d 558, 561 (Colo. App. 2000).

¶ 31   Here, Dr. Bernton testified and opined that “approximately

  one-third” of claimant’s knee condition was caused by work-related

  factors. He also unequivocally stated that it was his opinion

  “beyond a reasonable degree of medical probability, [that] the

  osteoarthritis would be there and the need for treatment with or

  without the occupational activity.” And Dr. Hughes, claimant’s

  retained physician, corroborated Dr. Bernton’s opinion that

  independent risk factors, including claimant’s “weight, family


                                     17
  history and idiopathic knee osteoarthritis” contributed to his

  developing “end stage osteoarthritis of the knees.” The ALJ found

  Dr. Bernton’s opinion credible and persuasive and noted that Drs.

  Bernton’s and Hughes’ opinions overlapped with respect to the

  causes of claimant’s disease. Because these credibility

  determinations are not “overwhelmingly rebutted by hard, certain

  evidence” to the contrary, we may not set them aside. See id.

¶ 32   Claimant nonetheless argues that the apportionment assigned

  by the ALJ was “speculative” and therefore “violative of the

  apportionment principles.” As outlined above, however, Dr.

  Bernton unambiguously stated in both his report and his testimony

  that “approximately one-third of [claimant’s] condition can be

  reasonably apportioned to the occupational exacerbation of his

  underlying condition and the other two-thirds of his condition can

  be apportioned to the other two risk factors which are present

  (osteoarthritis in multiple other sites and increased body mass

  index).” In our view, Dr. Bernton’s statements were concrete, not

  speculative.

¶ 33   In contrast, in each of the cases claimant cites to support his

  assertion that “speculative” apportionment cannot be upheld, the


                                   18
physicians admitted that their opinions were ambiguous, equivocal,

assumptive, or based on mere guesswork. In the absence of

concrete supporting statements, the physicians’ opinions were

deemed too speculative to support apportionment. See Parrish v.

Indus. Comm’n, 151 Colo. 538, 541-42, 379 P.2d 384, 385-86

(1963) (“[I]t was not error for the commission to refuse to allocate

any portion of claimant’s 5% disability to any alleged prior back

condition or injury” where there was “no evidence of what that

percentage should be” and physician testified that “he was unable

to tell how much of this injury was due to this accident and how

much to any previous back injury or condition.”); Empire

Oldsmobile, Inc. v. McLain, 151 Colo. 510, 513, 516, 379 P.2d 402,

403, 405 (1963) (The physician’s statement that an impairment

rating was an “assumption” and that “[i]t would be very difficult . . .

to give any accurate . . . rating” could not support the disability

impairment rating where the rating was made “on an arbitrary basis

of assumptions or guesses.”); Mathews v. Indus. Comm’n, 144 Colo.

146, 149, 355 P.2d 300, 301 (1960) (physician’s testimony that his

apportionment recommendation was “somewhat arbitrary” showed

his recommendation was “[m]ere conjecture” insufficient to support


                                  19
  apportionment). We therefore reject claimant’s argument that Dr.

  Bernton’s opinions were “too speculative” to support

  apportionment.

¶ 34   Rather, we conclude that substantial evidence supports the

  ALJ’s apportionment findings and hold that the Panel did not err

  when it declined to set aside the ALJ’s order on this basis. See

  Anderson, 859 P.2d at 825; Paint Connection Plus, 240 P.3d at 431;

  Duncan, 107 P.3d at 1002.

                                IV. Conclusion

¶ 35   The order is affirmed.

       JUDGE PLANK concurs.

       JUDGE BERGER specially concurs.




                                     20
       JUDGE BERGER, specially concurring.

¶ 36   I join the court’s opinion. I write separately only to address

  my concerns regarding apportionment of liability attributable to a

  claimant’s genetic predisposition to a disease when the genetic

  predisposition has not actually resulted in the disease.1

¶ 37   The majority correctly observes that apportionment is

  permissible under some circumstances. See, e.g., § 8-42-104(3),

  C.R.S. 2016.2 An employer is statutorily responsible only for

  injuries and disabilities caused by work injury or industrial

  exposure. Anderson v. Brinkhoff, 859 P.2d 819, 823 (Colo. 1993).

  In Anderson, the Colorado Supreme Court held that because

  occupational diseases may have both work-related and non-work-

  1  According to the National Cancer Institute, a genetic
  predisposition is an “[i]ncreased likelihood or chance of developing a
  particular disease due to the presence of one or more gene
  mutations and/or a family history that indicates an increased risk
  of the disease.” NCI Dictionary of Genetics Terms, Nat’l Cancer Inst.,
  https://perma.cc/MH99-WYKX; see also What Does it Mean to
  Have a Genetic Predisposition to a Disease?, U.S. Nat’l Library of
  Med., https://perma.cc/73BH-2XYZ.

  2 Some states have rejected apportionment entirely in workers’
  compensation cases. See Sullins v. United Parcel Serv., Inc., 108
  A.3d 1110, 1122 (Conn. 2015); Stephens v. Winn-Dixie Stores, Inc.,
  201 So. 2d 731, 736-37 (Fla. 1967); Newberg v. Armour Food Co.,
  834 S.W.2d 172, 175 (Ky. 1992); Bond v. Rose Ribbon & Carbon
  Mfg. Co., 200 A.2d 322, 323-24 (N.J. 1964).

                                   21
  related causes, an employer may be liable for only a portion of a

  claimant’s occupational disease.

¶ 38   I agree that apportionment was permissible under Colorado

  law in this case. Not only did the evidence support the

  administrative law judge’s findings that the claimant’s osteoarthritis

  in his knees was caused in part by the non-work-related factors of

  his weight and family history, at least one doctor identified pre-

  existing osteoarthritis in other parts of the claimant’s body.

¶ 39   But apportionment of liability attributable to a person’s mere

  likelihood of developing a disease, without more, is impermissible.

  Genetic predispositions are measured by statistical probabilities; for

  example, a woman or man who carries abnormalities in the BRCA1

  or BRCA2 genes has a much greater chance of developing breast

  and ovarian cancer than a woman or man who does not carry those

  abnormalities.3 BRCA1 and BRCA2: Cancer Risk and Genetic

  Testing, Nat’l Cancer Inst., https://perma.cc/U3W6-DH49; What




  3  I am not speaking here of genetic disorders that invariably cause
  a disease or condition. I am speaking only of genetic
  predispositions, which, while they increase the statistical likelihood
  of disease, do not invariably lead to disease.

                                     22
  Does it Mean to Have a Genetic Predisposition to a Disease?, U.S.

  Nat’l Library of Med., https://perma.cc/73BH-2XYZ.

¶ 40   Genetic predispositions are not, however, certainties. If a

  person has a ninety percent statistical likelihood of developing a

  particular disease (an unusually high predisposition), that also

  means that any given person with that genetic makeup may be one

  of the lucky ten percent who never develops the disease. Without

  evidence that the person’s predisposition to development of the

  disease has manifested itself in the disease, apportionment is

  inappropriate.

¶ 41   To permit apportionment under these circumstances would be

  fatally inconsistent with the workers’ compensation principle that

  an employer takes the employee as it finds him or her. Cowin & Co.

  v. Medina, 860 P.2d 535 (Colo. App. 1992); see § 8-42-104(3) (“An

  employee’s temporary total disability, temporary partial disability,

  or medical benefits shall not be reduced based on a previous

  injury.”); see also Stephens v. Winn-Dixie Stores, Inc., 201 So. 2d

  731, 737 (Fla. 1967) (“[T]he theory of apportionment is diametrically

  opposite to the injunction that ‘the employer takes the employee as

  he finds him.’”). Instead of taking the employee as the employer


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  finds her, it would do precisely the opposite by burdening an

  employee who may never develop the disease for which she has a

  predisposition and penalizing her for the existence of that family

  history or her genes.

¶ 42   The collateral ramifications of such apportionments are also

  troubling. If apportionments based solely on genetic

  predispositions were permissible, what would stop an employer

  from seeking and obtaining a blood draw from a claimant and

  having the blood tested for genetic disease markers? Most

  employees would find this degree of intrusion into their most

  personal affairs shocking. And, if the genetic test results are even

  remotely related to the claimed work-related injury or disease, the

  employer or its insurer almost certainly would seek apportionment.

¶ 43   Nothing in the Workers’ Compensation Act of Colorado, nor

  any Colorado Supreme Court case, authorizes apportionment based

  on a genetic predisposition that has not resulted in the disease. In

  my view, nothing in the court’s opinion should be read to authorize

  such an apportionment.




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