01 February 2014

Another useless indicator creeps in

Social Policy Bonds embody two main principles: targeting outcomes; and the use of markets to achieve these outcomes most efficiently. Even if discussion of Social Policy Bonds just leads to a rational discussion of which outcomes we want to achieve, then my work on the bonds would not be in vain.

I've discussed the futility of over-narrow objectives before, when discussing  Social Impact Bonds. (See also why I think the bonds must be tradeable.) But broad indicators too can, by default, become de facto targets, and they can be similiarly flawed; by which I mean that they are not inextricably linked to society's well-being. We have a tendency not to think through the implications of certain indicators: the biggest one is GDP. But another that is creeping into policymaking dicussion is five-year survival rates for cancer. The Economist casually slips it into an article about managing heatlh care:
Deciding where to seek treatment might seem simple for a German diagnosed with prostate cancer. The five-year survival rate hardly varies from one clinic to the next.... Need to know, 'the Economist', 2 February
But the five-year survival rate is meaningless:
[I]n the U.S. prostate cancer is being diagnosed earlier, a lead-time bias, and the cancer is being over diagnosed, that is, a pseudodisease is detected" in the form of screening-detected abnormalities that "meet the pathologic definition of cancer but will never progress to cause symptoms in the patient’s lifetime." Source (Scroll down to Incorrect metrics.)
The article in the Economist ends:
[D]octors ... have long focused on clinical outcomes such as infection and re-admission rates. But by thinking about what matters to patients, providers can improve care and lower costs at the same time.
Exactly so. We need to be focusing on broad, meaningful indictors of well-being, such as Quality Adjust Life Years, and target those, rather than casually accept the use of flawed measures such as five-year survival rates. 

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