The determination of whether to proceed with medical intervention is usually done with a metric called quality adjusted life years (QALY: which is life years ad

The determination of whether to proceed with medical intervention is usually done with a metric called quality adjusted life years (QALY: which is life years adjusted by quality of life), or rather they are never done if QALY is negative. And proceed to make a judgement call based on QALY/cost. As for studies, almost every cancer treatment study will use this metric as will _many_ other medical studies.