Before Justices Saitta, Hardesty and Parraguirre. Opinion by Justice Hardesty.
In this appeal, the Nevada Supreme Court considered the proper method of calculating permanent partial disability (PPD) compensation for a subsequent work-related injury when the impairment rating for the subsequent injury is based upon a different edition of the applicable guide than were prior injuries. Nevada’s Division of Industrial Relations requires PPD awards to be based on a percentage of whole person impairment as determined by a rating physician, who makes the calculations using the current edition of the American Medical Association’s Guides to the Evaluation of Permanent Impairment. The employee, Dale Blake, injured his back during the course and scope of his employment in 2004, and had previously suffered four previous industrial accidents involving back injuries as recently as 1995. In the 1995 injury, Blake’s PPD benefits were determined by using the second edition of the AMA Guide, resulting in a determination of a 14-percent impairment. In 2003, the Legislature mandated that the fifth edition of the AMA Guides be used, and therefore for his 2004 injury, Blake’s benefits were determined by using the fifth edition of the AMA Guides resulting in a 40-percent whole person impairment, and then subtracting the previous 14-percent, and concluding that Blake’s benefits should be calculated based on a net 26-percent increase. Based on an objection by the carrier/employer, the doctor recalculated Blake’s benefits by estimating the percentage of impairment from the 1995 injury using the 2003 AMA Guide, rather than simply accepting the previous estimation based on the earlier Guide, resulting in a benefits calculation based on a net 17-percent increase. Blake challenged this decision, and ultimately the district court ruled on a petition for judicial review that the prior percentage of disability should be deducted from the current disability percentage regardless of which edition of the AMA Guide was used to calculate the prior disability determination. The Court disagreed with this approach, holding that the plain language of NRS 616C.490(9) requires that the calculations for prior and subsequent injuries be reconciled by using the current edition of the AMA Guides to determine the percentages of the current and previous disabilities, and then subtracting the percentage from the previous impairment from the percentage from the current impairment to calculate the award for the current injury. Applying this formula to this case, the Court ruled that the second calculation resulting in a net 17-percent increase was the correct one. The Court further held that to the extent NAC 616C.490 allows for computation of the PPD compensation without reconciliation of the different editions of the AMA Guides, it conflicts with NRS 616C.490 and is invalid. (Megan Starich, Associate in the Reno office of McDonald Carano Wilson LLP).
