HRS 386-3 (1993), provides, in pertinent part, that if an employee suffers personal injury either by accident arising out of and in the course of the employment or by disease proximately caused by or resulting from the nature of the employment, the employee's employer or the special compensation fund shall pay compensation to the employee or the employee's dependents as hereinafter provided. In addition,HRS 386-85(1) (1993) provides that "in any proceeding for the enforcement of a claim for compensation under this chapter it shall be presumed, in the absence of substantial evidence to the contrary . . . that the claim is for a covered work injury". The Hawaii Supreme Court has explained that HRS 386-85 clearly dictates that coverage will be presumed at the outset, subject to being rebutted by substantial evidence to the contrary. This is so in all claims proceedings, regardless of the existence of conflicting evidence, as the legislature has determined that where there is a reasonable doubt as to whether an injury is work-connected, it must be resolved in favor of the claimant. Akamine v. Hawaiian Packing & Crating Co., 53 Haw. 406, 495 P.2d 1164, 409, 495 P.2d 1164, 1166. Flor v. Holguin, Hawaii, 93 Haw. 245, 999 P.2d 843 (May 30, 2000), reconsideration granted in part on other grounds, Hawaii, 94 Haw. 11, 6 P.3d 809 (2000), (quoting Chung v. Animal Clinic, Inc., 63 Haw. 642, 650-51, 636 P.2d 721, 726-27 (1981)). "This presumption has been described as one of the 'keystone principles' of our workers' compensation plan." Id. at, P.3d at (citing Iddings v. Mee-Lee, 82 Haw. 1, 22, 919 P.2d 263, 284 (1996)(Ramil, J., dissenting)). In addition to the presumption of compensability, the broad humanitarian purpose of the workers' compensation statute read as a whole requires that all reasonable doubts be resolved in favor of the claimant, . . . for diseases arising from the nature of the employment are among the costs of production which industry must bear. . . . Thus, an injury is compensable if it reasonably appears to have resulted from the working conditions.Id. at, P.3d at (quoting Lawhead v. United Air Lines, 59 Haw. 551, 560, 584 P.2d 119, 125 (1978)) The supreme court has further held that for an injury to be compensable under a workers' compensation statute, there must be a requisite nexus between the employment and the injury. The nexus requirement is articulated in Hawaii, as in the majority of jurisdictions, on the basis that, to be compensable, an injury must arise out of and in the course of employment. Id. at, P.3d at (quoting Tate v. GTE Hawaiian Telehone Co., 77 Haw. 100, 103, 881 P.2d 1246, 1249 (1994). In determining whether an injury meets this criterion, the court has adopted a "unitary" test that considers whether there is a sufficient work connection to bring the accident within the scope of the statute. . . . the work connection approach simply requires the finding of a causal connection between the injury and any incidents or conditions of employment.Id. at, P.3d at. Furthermore, the statutory presumption imposes upon the employer the burden of going forward with the evidence and the burden of persuasion. . . . the employer may overcome the presumption only with substantial evidence that the injury is unrelated to the employment. . . . Evidence, to be substantial, must be credible and relevant. Tate, 77 Haw. at 107, 881 P.2d at 1253. The supreme court has explained that the claimant must prevail if the employer fails to adduce substantial evidence that the injury is unrelated to employment. The term "substantial evidence" signifies a high quantum of evidence which, at the minimum, must be "relevant and credible evidence of a quality and quantity sufficient to justify a conclusion by a reasonable person that an injury or death is not work connected." Flor, Hawaii at, P.3d at (quoting Akamine, 53 Haw. 406 at 408-09, 495 P.2d at 1166).