What is the test for indifference in prison medical care?

Jett v. Penner, 439 F.3d 1091, 1096 (9th Cir.2006). The second part of the test is satisfied by "showing (a) purposeful act or failure to respond to a prisoner's pain or possible medical need and (b) harm caused by the indifference." Id. "Indifference may appear when prison officials deny, delay or intentionally interfere with medical treatment, or it may be shown by the way in which prison physicians provide medical care.... Yet, an inadvertent [or negligent] failure to provide adequate medical care alone" is insufficient. Id. (citations omitted).