Opinion ID: 2514034
Heading Depth: 3
Heading Rank: 1

Heading: Risk Factors: Epidemiological Evidence

Text: ¶ 24 To determine whether Brewer's carpal tunnel syndrome was caused by his work as a clerk at Denver & Rio Grande, Dr. Harrison examined two risk factors, repetitive typing and inappropriate posture due to the railroad's furniture. Dr. Harrison explained that repetition is a factor . . . well known to cause carpal tunnel syndrome. Similarly, Dr. Harrison attested that, if combined with other risk factors, poor posture in the form of wrist extension such as that exhibited by Brewer can cause carpal tunnel syndrome by placing stress across the wrist and causing eventual damage to the nerve. Moreover, Dr. Harrison testified, when both of these risk factors are present, they combine to work synergistic[ally], exacerbating the potential effect one factor would have had on the wrist by itself. ¶ 25 In support of his examination of these two risk factors, Dr. Harrison relied on a recent epidemiological literature review conducted by NIOSH, which addressed four risk factors as potential causes of carpal tunnel syndrome: repetition, force, posture, and vibration. That review concludes, There is strong evidence for a relationship between exposure to a combination of risk factors (e.g., force and repetition, force and posture) and CTS [carpal tunnel syndrome]. . . . Based on the epidemiological studies reviewed above, especially those with quantitative evaluation of the risk factors, the evidence is clear that exposure to a combination of job factors studied (repetition, force, posture, etc.) increases the risk for CTS. This is consistent with the evidence that is found in the biomechanical, physiological, and psychosocial literature. Nat'l Inst. for Occupational Safety and Health, U.S. Dep't of Health and Human Services, Publication No. 97-141, Musculoskeletal Disorders and Workplace Factors: A Critical Review of Epidemiological Evidence for Work-Related Musculoskeletal Disorders of the Neck, Upper Extremity, and Low Back 5a-28 (Bruce P. Bernard ed., 1997) (emphasis in original). In addition to this review, Dr. Harrison testified at trial that he had relied on dozens of other studies finding repetition and posture to be risk factors for carpal tunnel syndrome. For instance, one article co-authored by Dr. Harrison and published in the Journal of the American Medical Association described six potential risk factors connected with carpal tunnel syndrome. That article states, Work-related risk factors associated with [cumulative trauma disorders] include (1) repetition, (2) high force, (3) awkward joint posture, (4) direct pressure, (5) vibration, and (6) prolonged constrained posture. For example, . . . [k]eyboard use often requires wrist extension, ulnar deviation, and sustained localized pressure at the wrist crease. David M. Rempel et al., Work-Related Cumulative Trauma Disorders of the Upper Extremity, 267 JAMA 838, 838 (1992). Likewise, another article authored by Denver & Rio Grande's own expert witness, Dr. Moore, analyzed repetitive forceful exertions, repetitive static exertions, awkward postures, hand-arm vibration, localized mechanical compression, and various combinations of these variables as risk factors for development of carpal tunnel syndrome. See J. Steven Moore, Clinical Determination of Work-Relatedness in Carpal Tunnel Syndrome, 1 J. Occupational Rehabilitation 145, 155 (1991). ¶ 26 Despite this evidence, Denver & Rio Grande argues that because Dr. Harrison also professed to rely on an article entitled Methodological Limitations in the Study of Video Display Terminal Use and Upper Extremity Musculoskeletal Disorders, which found in part that [m]ethodological limitations and inconsistent results have limited conclusions that can be made from . . . studies of the associations between keyboard use and upper extremity disorders, he erred in applying the second step of the 1979 NIOSH methodology by failing to rely on epidemiological evidence supporting his assessment of what risk factors may have influenced the onset of Brewer's carpal tunnel syndrome. Fredric Gerr et al., Methodological Limitations in the Study of Video Display Terminal Use and Upper Extremity Musculoskeletal Disorders, 29 Am. J. Indus. Med. 649, 649 (1996). However, the substance of this article attempts, not to discredit the risk factors a doctor might use to assess the cause of a specific patient's carpal tunnel syndrome, but to establish the need for additional standardized studies to determine more precisely how much exposure to video display terminal use may lead to repetitive disorders such as carpal tunnel syndrome generally. See id. at 654-55 (Research to determine associations between VDT [video display terminal] use and upper extremity disorders will contribute maximally to our understanding only if measures of both exposure . . . and adverse health effect . . . are standard, objective, and valid.). More importantly, Dr. Harrison's mere citation to this study cannot now undermine the trial court's determination that he correctly followed step two of the 1979 NIOSH methodology if the court had before it other sufficient foundational evidence upon which it could have determined Dr. Harrison properly assessed the epidemiological risk factors relevant to the facts of this case. As explained above, we review such determinations `under an abuse of discretion standard,' State v. Brown, 948 P.2d 337, 340 (Utah 1997) (quoting State v. Larsen, 865 P.2d 1355, 1361 (Utah 1993)), and we will reverse `only if . . . no reasonable [person] would take the view adopted by the trial court.' Id. (quoting State v. Gerrard, 584 P.2d 885, 887 (Utah 1978)). Accordingly, in light of Dr. Harrison's reliance on the NIOSH literature review study finding strong evidence for a relationship between exposure to a combination of risk factors, such as repetition and posture, and carpal tunnel syndromealong with his reference to two other articles employing the very risk factors he used in determining the cause of Brewer's ailmentwe cannot say that the trial court abused its discretion by rejecting Denver & Rio Grande's arguments that Dr. Harrison failed to properly apply step two of the 1979 NIOSH methodology to the facts of this case.