Doctor, professor, and writer on health policy issues, Aaron Carroll recently examined the issues with how cancer research is evaluated in the US. Survival rates are used more often than mortality rates as measures of effectiveness, however, survival rates are often indicative of early diagnoses caused by more advanced scanning procedures and not by better treatments or real improvements.
Compared to other counties, the US spends more on each year of quality adjusted life (QALY). While improving QALY is clearly something we should strive for, the astronomical costs of healthcare in the US may force us to rethink how to diversify research spending. For starters, we should be using measurements that adequately evaluate the effectiveness of treatments. Another useful step would be for more people to create living wills to clarify their wishes in regards to end of life care. This may help decrease costs in one of the most expensive areas of medicine.
But the mortality rate remains unchanged, because the same relative number of people are dying every year. We’ve just moved up the time of diagnosis and potentially subjected people to five more years of therapy, increased health care spending and caused more side effects... But if we just looked at survival rates, we would think we made a difference. Unfortunately, that happens far too often in international comparisons... The second problem with using survival rates is overdiagnosis bias... That means some subclinical cases that would never lead to death are now being counted as diagnoses. Since they were never dangerous, and we’re now picking them up by scans, they’re improving our survival rates. But they do nothing for mortality rates because no fewer people are dying.