In medicine, we are often perilously mired in first order choices, to the detriment of patients. We act as though there are just simple binary choices to make, such as treatment and life versus no treatment and death. Would that it were so simple.
Someone I knew, a decade ago, made a courageous choice. Faced with the grim prognosis of an aggressive metastatic cancer, he elected to forego any treatment and take his chances. He left the hospital and got one month of relative freedom from medical burdens. He got his affairs in order. He selected his own grave site. He visited with friends and family and doubtless did countless other things that he could not have done had he elected to receive chemotherapy and or radiation or debulking surgery or basically any medical intervention given the desperate nature of his case. His last month could have been characterized by painful procedures and repeated scans, nausea, vomiting, and anorexia induced by chemotherapy, cumbersome trips to radiotherapy - you get the picture. In another parallel universe his doppelganger, selecting "treatment" for this runaway cancer, would have traded away the last month of his life - and probably would not have benefited from the trade. An opportunity lost is an opportunity cost.
Let's look at another case. An 82 year old frail man on dialysis for several months presents with increasing fluid in the chest around the lungs Initial (non-invasive) testing suggests malignancy/cancer. The patient can be steered in several directions ranging from hospice (given age, functional status, and co-morbidities, the prognosis is poor), to straightforward diagnosis via needle biopsy sampling (of fluid or superficial lymph nodes) followed by consideration of treatment options, or to aggressive video assisted thoracic surgery under general anesthesia to take control of the fluid, scar down the lung to prevent recurrence, and get a definitive diagnosis by surgical biopsy.
Note that as the aggressiveness of the diagnostic and treatment approach increases, so does the likelihood of never leaving the hospital as a result of complications. An opportunity lost is an opportunity cost. And the patient who selects or is steered towards the most aggressive treatment option may well pay with their final days for the marginal chance of improving their outcome - measured, of course, in the number of days that they can live unencumbered at the end of their lives. In this case, regretfully, an aggressive approach was taken, and the patient died in the hospital, on life support.
We have to be very cognizant of these costly lost opportunities when we present options to patients, lest they double down with their final days.