What is the test for foreseeability in a medical malpractice case?

"[t]he degree of foreseeability necessary to warrant the finding of a duty will thus vary from case to case. For example, in cases where the burden of preventing future harm is great, a high degree of foreseeability may be required. [Citation.] On the other hand, in cases where there are strong policy reasons for preventing the harm, or the harm can be prevented by simple means, a lesser degree of foreseeability may be required. [Citation.]" (Gomez v. Ticor, supra, 145 Cal.App.3d at pp. 629-630, 193 Cal.Rptr. 600.)