IN THE COURT OF APPEALS OF IOWA
No. 20-0742 Filed June 16, 2021
DES MOINES PUBLIC SCHOOLS and EMC RISK SERVICES, LLC-TPA, Plaintiffs-Appellees,
vs.
THOMAS HILDRETH (deceased) by JANE HILDRETH (spouse), Defendant-Appellant. ________________________________________________________________
Appeal from the Iowa District Court for Polk County, David Porter, Judge.
Jane Hildreth, on behalf of her deceased husband, Thomas Hildreth,
appeals the district court’s reversal of the workers’ compensation commissioner’s
award of death benefits. REVERSED.
Jerry Jackson of Moranville & Jackson, P.C., West Des Moines, for
appellant.
Valerie A. Landis of Hopkins & Huebner, P.C., Des Moines, for appellees.
Heard by Schumacher, P.J., Vaitheswaran and Greer, JJ. 2
SCHUMACHER, Judge.
Jane Hildreth, on behalf of her deceased husband, Thomas Hildreth,
appeals from the district court’s reversal of the workers’ compensation
commissioner’s award of death benefits. We find the district court erred in
reversing the commissioner’s award and in determining the commissioner’s
decision was unsupported by substantial evidence. Accordingly, we reverse the
judgment entered by the district court and reinstate the commissioner’s decision.
I. Facts & Prior Proceedings
A. On October 11, 2013, Thomas Hildreth was admitted to the hospital after
suffering a stroke. Hildreth died on October 16, five days later. He was sixty-six
years old.
Approximately two years earlier, Hildreth sustained a traumatic brain injury.
On August 26, 2011, Hildreth slipped and fell on a wet floor at Des Moines East
High School, where he was a teacher and football coach. As a result of the fall,
Hildreth tore his right rotator cuff, herniated a disc in his lumbar spine, and was
rendered unconscious. He was taken to the hospital, where treating physicians
observed an abrasion on the right frontal region of Hildreth’s head and diagnosed
him with a concussion. A magnetic resonance imaging (MRI) scan of Hildreth’s
head was conducted at the time and returned normal results.
The injury was accepted as a workplace injury. After the fall, Hildreth
reported experiencing migraines, issues with memory and vision, tinnitus,
irritability, and difficulty sleeping. The migraines were so severe he would
sometimes vomit. He temporarily lost sight in his left eye. He also experienced
pain and stiffness in his neck, shoulder, and lower back. Hildreth sought treatment 3
for his symptoms. In November 2011, he was prescribed migraine medication for
his post-concussion headaches. He saw an otolaryngologist who found it logical
that his tinnitus resulted from head trauma and recommended hearing aids.
Hildreth also underwent physical therapy to address his pain and stiffness. On
April 11, 2012, Hildreth underwent a psychological evaluation, which showed no
evidence of cognitive dysfunction. By July 2012, the headaches and migraines
were reported to be improving.
On July 13, 2012, Hildreth retired from the Des Moines Public Schools.
Hildreth and his wife purchased a home in Arizona. Throughout the remainder of
2012 and into 2013, Hildreth continued to experience negative symptoms,
including neck and back pain. He received injections and steroid bursts, and
continued with physical therapy. On March 8, 2013, he underwent surgery to
address the pain in his lower back. Despite the surgery, Hildreth continued to
experience pain in his lower back, and some of his symptoms seemed to be
worsening.
On October 11, 2013, slightly over two years past his fall, Hildreth was
admitted to the hospital with signs of a stroke. A computerized tomography (CT)
scan of the brain was conducted and showed “possible acute right basal ganglia
infarct.” The scan also showed a previous injury in the right parietal and left
cerebellar regions, suggesting a previous stroke. Treatment was provided but
Hildreth passed away on October 16. The immediate cause of death as identified
by the death certificate was an “acute basilar artery infarction” with “etiology
uncertain.” 4
B. Hildreth’s surviving spouse1 filed a petition in arbitration seeking death
benefits, medical expenses, and costs arising out of Hildreth’s death. Des Moines
Public School denied there was a causal link between the injury suffered by
Hildreth in 2011 and the stroke which lead to his death.
On June 21, 2017, the case was submitted before the deputy workers’
compensation commissioner. Both parties offered reports from medical experts
concerning the relationship between traumatic brain injury and stroke. Hildreth
presented opinion letters from three experts: Dr. Marc Hines,2 Dr. Jamey Joe
Hawk,3 and Dr. Francis Miller.
Of the experts offered by Hildreth, the deputy commissioner found the
opinion of Dr. Miller the most compelling. Dr. Miller is a professor of internal
medicine with the division of cardiology at Duke University and at the Durham
Veterans Administration Hospital. Dr. Miller offered an initial medical report and a
follow-up report responding to the opposing expert.
In his report, Dr. Miller analyzed the medical records of Hildreth and
considered the medical research regarding the relationship between concussions
and strokes. First, Dr. Miller noted that Hildreth did not have the traditional risk
factors for stroke, pointing out that Hildreth’s documented blood pressure was
1 Also referred to as “Hildreth.” 2 Dr. Hines is a neurologist who provided a medical literature review in which he summarized numerous studies and academic articles, explaining their relative strengths and weaknesses. Dr. Hines concluded that based on Hildreth’s medical history and the literature available, Hildreth was at risk of stroke as a result of his mild traumatic brain injury. 3 Dr. Hawk is a Director of Urgent Care at the Iowa Clinic. In his report, Dr. Hawk
reviewed Hildreth’s medical records and the articles cited by the other experts and concluded that Hildreth’s traumatic brain injury likely would have played a significant part in contributing to his stroke. 5
within the normal range, he had no history of tobacco use, no
hypercholesterolemia, no clinical evidence of coronary or peripheral vascular
disease, and at the time of the stroke, displayed no evidence of atrial fibrillation or
other conditions associated with cardio embolic events.
Dr. Miller then addressed the relationship between traumatic brain injury
and stroke. He explained that traumatic brain injury “can result in functional and
structural damage to the vasculature” and that based on his experience and
medical research, this may increase one’s risk of stroke. Accordingly, because
Hildreth did not show the typical risk factors for stroke and because a prior
traumatic brain injury may increase the risk of stroke, it was Dr. Miller’s opinion that
Hildreth’s injury in 2011 was a significant contributing factor to his stroke and
death.
Dr. Miller’s report cited several articles and studies, which show an
increased risk of stroke following a traumatic brain injury. Specifically, Dr. Miller
cited “a nationwide, population-based, case cohort study published in the highly
respected peer-review journal Stroke,” which showed “that after adjusting for
sociodemographic characteristics and comorbidities, a diagnosis of traumatic brain
injury was independently associated with a 10.2, 4.6, and 2.3-fold increased risk
of subsequent stroke during 3 months, 1 year, and 5 years of follow-up,
respectfully.”4 Dr. Miller also cited to a “subsequent study involving over 25,000
subjects” which “found an increased risk of stroke in individuals with a more mild
4 Chen YH, et al., Patients with traumatic brain injury: population-based study suggests increased risk of stroke, 42 Stroke 2733 (2011). 6
form of traumatic brain injury than that suffered by Mr. Hildreth.”5 Finally, Dr. Miller
noted, “[r]eview of high-quality studies published in peer-reviewed journals provide
growing evidence that a prior history of traumatic brain injury increases the
subsequent risk of stroke.”6
Des Moines Public Schools offered it’s own expert, Dr. Michael Jacoby, to
rebut the assertions of Hildreth’s experts. Dr. Jacoby is a Director of Medical
Education at the Mercy Neuroscience Department and an Adjunct professor of
neurology at the Des Moines University Medical School. He offered an initial
medical report and also testified at the hearing before the deputy commissioner.
Dr. Jacoby concluded that Hildreth’s death was not due to a remote traumatic
event.
In his report, Dr. Jacoby explained that strokes attributable to head trauma
occur near the time of the traumatic event and are due to “cervicocephalic
dissection of blood vessels”—i.e., rupture of an artery. The type of stroke suffered
by Hildreth was due to “thrombus resulting in occlusion of a critical intracranial
blood vessel”—i.e., a blood clot blocking an artery. It was, therefore, Dr. Jacoby’s
opinion that it would be incorrect to conclude that the traumatic brain injury suffered
by Hildreth two years prior was a substantial contributing factor to his stroke.
Additionally, Dr. Jacoby pushed back on the notion that Hildreth did not
exhibit risk factors for stroke. Primarily he noted that Hildreth “was in his 60s at
5 Liu SW, et al., Increased Risk of Stroke in Patients of Concussion: A Nationwide Cohort Study, 14 Int’l. J. Env’t Rsch. Pub. Health 230 (2017). 6 Dr. Miller cites a study from the American Academy of Neurology’s journal
“Neurology.” The study is discussed and relied on by the other experts, the deputy commissioner, and the district court. Burke JF, et al., Traumatic brain injury may be independent risk factor for stroke, 81 Neurology 33 (2013). 7
the time of his death, a time of great stroke risk.” Dr. Jacoby also noted that the
medical records available to him largely related to Hildreth’s musculoskeletal
issues and were rather limited in regard to his general health over time and
suggested that Hildreth may have exhibited other risk factors that were not
documented in the records.
Dr. Jacoby ended his report by stating, “No reasonable evidence exists to
support a relationship between trauma of any sort and stoke years later” and noting
that there is “significant medical literature to support the increased risk of stroke
through a natural process of aging.” Dr. Jacoby concluded that he is “unable to
identify a direct correlation between any injury and the stroke.”
Dr. Jacoby also offered in-person testimony at the hearing and commented
on the methodology used in some of the studies cited by Dr. Miller, noting the
limitations of retrospective analysis and the potential for selection bias. Dr. Jacoby
testified that while the studies showed an interesting connection, more research
was necessary to establish a relationship and pointed out that the authors of the
studies acknowledged as much.
Dr. Miller responded to Dr. Jacoby’s opinion in a follow-up report. Dr. Miller
agreed that strokes occurring at the time of head trauma are often associated with
arterial dissection; however, he disagreed with the contention that because
Hildreth’s stroke was not due to dissection, his prior head trauma could not have
contributed to his stroke. He stated, “Dr. Jacoby agrees that the treating
physicians diagnosed Mr. Hildreth with concussion but fails to acknowledge in his
report the association between concussion and risk of subsequent stroke.” Dr. 8
Miller maintained that “a prior diagnosis of concussion substantially increases the
risk of subsequent stroke.”
C. In its decision, the deputy commissioner considered the experts’
opinions and noted that research into the connection between traumatic brain
injury and stroke is in its early stages and that further study is necessary to
establish a medical consensus. The deputy wrote, “This is a very difficult decision.
Dr. Jacoby’s in-person testimony was convincing. The medical literature does not
draw a definitive conclusion.”
The deputy reasoned,
The studies, while new, are based on a large population. The [study published in the International Journal of Research and Public Health7] was nationwide, population-based. The [study published in Neurology8] study involved over a million subjects. Dr. Jacoby [sic] points out [sic] that these studies are not prospective and therefore lack some direct correlation to the decedent’s circumstances, the studies did take into account demographics, vascular risk factors, comorbidities, trauma severity, and trauma mechanism.
Ultimately, the deputy commissioner concluded, “The decedent’s medical
condition at the time of his death, combined with the concussive incident on August
26, 2011, most closely aligns with the opinions of Dr. Miller and the subsequent
medical literature.” The deputy commissioner further noted, “However, the
standard in these cases is by a preponderance of the evidence or rather, more
likely than not.”
7 Liu SW, et al., Increased Risk of Stroke in Patients of Concussion: A Nationwide Cohort Study, 14 In’t J. Env’t Rsch. Pub. Health 230 (2017). 8 Burke JF, et al., Traumatic brain injury may be independent risk factor for stroke,
81 Neurology 33 (2013). 9
The deputy commissioner ordered Des Moines Public Schools to pay death
benefits to Jane according to Iowa Code section 85.31 (2017) and reimbursement
for medical bills. Des Moines Public Schools appealed the deputy commissioner’s
decision. On April 10, 2019, the workers’ compensation commissioner affirmed
the deputy commissioner’s findings. On May 9, Des Moines Public Schools
petitioned the district court for judicial review of the agency’s findings.
On April 21, 2020, the district court granted judicial review and reversed the
decision of the workers’ compensation commissioner.9 Jane Hildreth, on behalf of
her husband, Thomas, appeals.
II. Standard of Review
A final judgment rendered by a district court under chapter 17A is reviewed
for errors of law. Iowa Code § 17A.20; Iowa R. App. P. 6.907. The Iowa
Administrative Procedure Act confers to the district court the power of judicial
review over final agency action. Iowa Code § 17A.19(1); Foods, Inc. v. Iowa C.R.
Comm’n, 318 N.W.2d 162, 164 (Iowa 1982).
Acting in this capacity, the district court may only interfere with the
commissioner’s decision if it is erroneous under one of the grounds enumerated in
section 17A.19(10). In our review of the district court, we apply “the standards of
section 17A.19(10) to the agency action to determine whether this court’s
conclusions are the same as those of the district court.” Foods, Inc., 318 N.W.2d
at 165 (quotation omitted).
9 The transcript from the hearing on the petition for judicial review is not contained in this record. 10
III. Analysis
A. In the present case, the district court reversed the commissioner’s
decision affirming the deputy commissioner’s finding that the concussion incident
suffered by Hildreth was a substantial contributing factor in his stroke and ultimate
death. In reversing the commissioner’s decision, the district court rejected the
opinion of Hildreth’s expert witness, Dr. Miller, and found that without this evidence,
substantial evidence did not exist in the record to support the deputy
commissioner’s findings.
Medical causation presents a question of fact that is “vested in the discretion
of the workers’ compensation commission.” Cedar Rapids Cmty. Sch. Dist. v.
Pease, 807 N.W.2d 839, 844–45 (Iowa 2011). A court may only disturb the
commissioner’s finding of fact if it is not supported by substantial evidence. Id.;
Iowa Code § 17A.19(10)(f).
Under section 17A, substantial evidence is defined as “the quantity and
quality of evidence that would be deemed sufficient by a neutral, detached, and
reasonable person, to establish the fact at issue when the consequences resulting
from the establishment of that fact are understood to be serious and of great
importance.” Iowa Code § 17A.19(10)(f )(1). In properly applying the substantial-
evidence standard to an agency’s factual determination, our supreme court has
explained,
Evidence is not insubstantial merely because different conclusions may be drawn from the evidence. To that end, evidence may be substantial even though we may have drawn a different conclusion as fact finder. Our task, therefore, is not to determine whether the evidence supports a different finding; rather, our task is to determine whether substantial evidence, viewing the record as a whole, supports the findings actually made. 11
Pease, 807 N.W.2d at 845 (internal citations omitted).
B. The district court’s reasoning was based on its contention that the
studies and theories Dr. Miller relied upon in forming his opinion were “not to a
reasonable degree of medical certainty.” In particular, the district court took issue
with two of the studies cited by Dr. Miller in his opinion letter. In rejecting the first
study,10 the district court found that the study was “based on research that used
objectionable methodology not appropriate for this type of scientific study,
including retrospective analysis, selection bias, and a lack of definition of
concussion or traumatic brain injury and of stroke as referred to in these studies.”
The district court rejected the second study11 because the authors of the article
“injected uncertainty in their own conclusions by acknowledging the need for
additional studies concerning the connection between traumatic brain injuries and
strokes.”
The district court found the opinion offered by Dr. Miller was “based on
evidence that, at this stage, is merely conjectural,” as the studies “simply opened
a discussion in the medical community,” which is “not the same as drawing a
conclusion to a reasonable degree of scientific certainty.” The district court found
it “immaterial” whether the deputy commissioner found the offered studies
compelling and stated that “[w]hat is material is whether the scientific and medical
communities have accepted the studies as scientifically or medically valid.”
10 Chen YH, et al., Patients with traumatic brain injury: population-based study suggests increased risk of stroke, 42 Stroke 2733 (2011). 11 Burke JF, et al., Traumatic brain injury may be independent risk factor for stroke,
81 Neurology 33 (2013). 12
Therefore, the district court excluded the expert opinion of Dr. Miller from its
substantial evidence analysis and concluded, Without that evidence, there is
insufficient evidence in the record to support the commission’s conclusion that the
stroke that claimed Mr. Hildreth’s life in October 2013, was causally related to the
concussion he sustained in August 2011.”
C. We find it was error for the district court to exclude from its analysis the
expert testimony of Dr. Miller. The question of medical causation presents a
question of probability and, in this case, “substantial contributing factors.” The
question is, therefore, often answered through the opinions of experts. Pease, 807
N.W.2d at 845 (“Medical causation is essentially within the domain of expert
testimony.” (quotation omitted)); Schutjer v. Algona Manor Care Ctr., 780 N.W.2d
549, 560 (Iowa 2010) (“Ordinarily, expert testimony is necessary to establish the
causal connection between the injury and the disability for which benefits are
claimed.”).
In establishing medical causation, absolute certainty may never be
achieved and is not required. Hansen v. Cent. Iowa Hosp. Corp., 686 N.W.2d 476,
485 (Iowa 1984) (finding it was error for the district court to exclude doctor’s expert
testimony on medical causation where the district court had concluded the
evidence was not “expressed to a medical degree of certainty” and “insufficient to
be admissible”). “Buzzwords like ‘reasonable degree of medical certainty’ are [sic]
not necessary to generate a jury question on causation.” Id. “A lack of absolute
certainty [in an expert’s opinion] goes to the weight of the expert’s testimony, not
to its admissibility.” Johnson v. Knoxville Cmty. Sch. Dist., 570 N.W.2d 633, 637
(Iowa 1997). 13
“[T]he determination of whether to accept or reject an expert opinion is
within the ‘peculiar province’ of the commissioner.” Pease, 807 N.W.2d at 845.
The admissibility of expert testimony is favored, and the rules of evidence are not
strictly applied in hearings before the commissioner. See Iowa Code § 17A.14(1)
(“A finding shall be based upon the kind of evidence on which reasonably prudent
persons are accustomed to rely for the conduct of their serious affairs, and may be
based upon such evidence even if it would be inadmissible in a jury trial.”); Ranes
v. Adams Lab’ys, Inc., 778 N.W.2d 677, 693 (Iowa 2010) (“[T]he factual basis of
an expert opinion goes to the credibility of the testimony, not the admissibility.”);
Leaf v. Goodyear Tire & Rubber Co., 590 N.W.2d 525, 530–31 (Iowa 1999) (“[W]e
are committed to a liberal view on the admissibility of expert testimony.”); Morrison
v. Century Eng’g, 434 N.W.2d 874, 877 (Iowa 1989) (“Strict rules of evidence are
not to be applied in proceedings before the industrial commissioner.”).
The commissioner is to consider the expert testimony in light of the
“accuracy of the facts relied upon by the expert and other surrounding
circumstances.” Schutjer, 780 N.W.2d at 560. The commissioner, as the fact
finder, determines the weight to be given to expert testimony. Id.; Sanchez v. Blue
Bird Midwest, 554 N.W.2d 283, 285 (Iowa Ct. App. 1996) (“Expert opinion
testimony, even if uncontroverted, may be accepted or rejected in whole or in part
by the trier of fact.”).
Hildreth presented three experts who offered their opinion regarding the
relationship between traumatic brain injury and stroke. Medical studies published
in peer-reviewed academic journals indicating an increased risk of stroke following 14
traumatic brain injury were introduced. The experts considered these studies and
explained their relative strengths and weaknesses.
The deputy commissioner considered the opinions of the experts and
evaluated the facts and sources they relied on. The deputy commissioner also
considered the medical records of Hildreth, which showed a lack of documented
stroke risk factors absent his age. The deputy commission noted that this was “a
very close case” but concluded the evidence “most closely aligns with the opinions
of Dr. Miller and the subsequent medical literature.”
The district court’s inquiry on judicial review is “closely and strictly
circumscribed.” Morrison, 434 N.W.2d at 876. An opposing expert’s testimony
explaining the limitations of certain types of methodology and an author’s
acknowledgment of the need for additional research into a particular medical field
does not warrant the exclusion of an expert’s testimony by the district court on
judicial review. In doing so, the district court engaged in a re-weighing of the
credibility of the experts and supplemented its judgment for that of the
commissioner. “[T]he court’s review is not de novo. The court must not reassess
the weight of the evidence because the weight of the evidence remains within the
agency’s exclusive domain.” Robbennolt v. Snap-On Tools Corp., 555 N.W.2d
229, 234 (Iowa 1996).
On judicial review it is not the district court’s role to weigh the credibility of
the experts before the commissioner; the legislature has vested this responsibility
with the commissioner. “Public interest demands that judicial hands must be kept
off administrative judgment calls.” Morrison, 434 N.W.2d at 876; Sellers v. Emp.
Appeals Bd., 531 N.W.2d 645, 646 (Iowa Ct. App. 1995) (“The administrative 15
process presupposes judgment calls are to be left to agency. Nearly all disputes
are won or lost there.”).
The substantial-evidence standard directs the court to determine whether
“substantial evidence in the record, viewed as a whole, supports the finding
actually made.” Pease, 807 N.W.2d at 845 (emphasis added). “Evidence is not
insubstantial merely because different conclusions may be drawn from the
evidence.” Id. We find the district court incorrectly reassessed the weight of the
evidence.
C. Upon our review, we find substantial evidence exists in the record when
viewed as a whole to support the commissioner’s decision and the deputy
commissioner’s findings. The deputy commissioner considered the testimony of
the experts, weighed the evidence presented, and rationally explained its
conclusion.
There is no requirement for the commissioner to find causation established
through a “reasonable degree of scientific certainty.” Hansen, 686 N.W.2d at 485
(“The rule is that expert testimony indicating probability or likelihood of a causal
connection is sufficient to generate a question on causation.”). The nature of
medical causation will depend on probability and is often answered through the
opinions of experts. Pease, 807 N.W.2d at 845. The credibility of the experts and
the reliability of the sources they rely on are to be weighed in light of all the relevant
facts by the commissioner, who may accept or reject in whole or in part the
evidence. Id.
It was within the preview of the deputy commissioner to accept the opinion
of Dr. Miller over the opposing expert. The record establishes that the deputy 16
commissioner sufficiently considered the qualifications of Dr. Miller, the strengths
and weaknesses of the sources he cited, and the opposing expert’s criticism of Dr.
Miller’s opinion. See Iowa Code § 17A.16(1); Broadlawns Med. Ctr. v. Sanders,
792 N.W.2d 302, 306 (Iowa 2010).
When the standard is properly applied, we find substantial evidence exists
to support the agency’s decision. “Because the commissioner is charged with
weighing the evidence, we liberally and broadly construe the findings to uphold his
decision.” Schutjer, 780 N.W.2d at 558; Second Injury Fund v. Bergeson, 536
N.W.2d 543, 546 (Iowa 1995) (“We broadly and liberally construe the
commissioner’s findings to uphold, rather than defeat the commissioner’s
decision.”).
IV. Conclusion
We find substantial evidence supports the workers’ compensation
commissioner’s decision. We find the district court erred in reversing the
commissioner’s award and in determining the commissioner’s decision was
unsupported by substantial evidence. Accordingly, the judgment entered by the
district court is reversed and the commissioner’s decision is reinstated.
REVERSED.