If a non-rabbi could decide what sofek pikuach nefesh means, could a doctor do it? I'm not sure, because I don't think the work of a doctor has much to do with calculating mortalities - that is more fittingly the work of an actuary or an epidemiologist. If you ask a doctor, given a certain presentation of symptoms, what is the chance that a certain patient sitting (or lying) in front of them will die, they will generally say, "It depends on the patient." Doctors are notoriously reluctant to give probabilities.
Even if doctors are reluctant to quote such possibilities, maybe they still practice according to them? The literature on medical decision-making gets broader every day, and I fear to tread where I am ignorant. I know enough though to say that it strongly depends on the specialty. Sometimes subspecialties of medicine differ so much from each other it's as if they are different professions altogether. The emergency-room doctor and the critical-care physician deal in life and death every day, while the outpatient practitioner has influence in the gradual development of healing or disease - these are broad generalizations, of course.