What is the test for medical malpractice in the context of the Eighth Amendment?

To prevail on an Eighth Amendment claim of medical mistreatment, an inmate must allege "acts or omissions sufficiently harmful to evidence deliberate indifference to serious medical needs." Estelle v. Gamble, 429 U.S. 97, 106 (1976). The indifference must be substantial; inadequate treatment due to negligence, inadvertence or differences in judgment between an inmate and medical personnel do not rise to the level of a constitutional violation. Id.; Franklin v. Oregon, 662 F.2d 1337, 1344 (9th Cir.1981).