It also awarded additional attorney fees to appellee for the continued unreasonable defense of the employee’s application for compensation. Upon appellate review, this Court must construe the evidence in the light most favorable to the party prevailing below, Crisp v. Brown’s Tysons Comer Dodge, Inc., 1 Va. App. 503, 504, 339 S.E.2d 916, 916 (1986), and the findings of fact made by the Workers’ Compensation Commission will be upheld when supported by credible evidence. James v. Capitol Steel Constr. Co., 8 Va. App. 512, 515, 382 S.E.2d 487, 488 (1989). However, the question of whether the disputed medical treatment was necessary within the meaning of Code § 65.2-603 is a mixed question of law and fact. See, e.g., City of Salem v. Colegrove, 228 Va. 290, 293, 321 S.E.2d 654, 656 (1984) (<HOLDING>). Accordingly, the commission’s conclusion as
holding that an error pertaining to a mixed question of law and fact under state law is not cognizable in a federal habeas proceeding holding that probable cause determination presents a mixed question of law and fact holding that joint employment determination was a complex mixed question of law and fact properly determined by jury holding reviewable as mixed question of law and fact determination that college education was not reasonable and necessary vocational rehabilitation training service under former code  65188 holding that the mixed question of exigent circumstance is reviewable de novo as a question of law