Many physicians think of "medical risks" in terms of the risk of accident or the risk of an untoward clinical outcome, or perhaps the lung cancer risk of a heavy smoker. Insurance physicians and actuaries use the term more broadly, as an idiom for medical impairments, conditions or risk factors with morbidity or premature mortality implications. This extensive two-volume document focuses on the latter concept.
Similarly, while practicing physicians talk about survival rates, this document homes in on mortality ratios (100 × number of deaths in interval/number of expected deaths) and excess death rates per 1000 per year (1000 × the difference between observed and expected number of deaths per person-years of exposure).
Why the difference? A 95% five-year survival rate for a group of 30-year-olds treated for a particular type of cancer sounds pretty good to clinicians (especially given