26 September 2015

Five-year survival rates: another Mickey Mouse indicator

Health statistics are tricky and, when they're used to make a case for increasing or diverting funding, we need to be especially vigilant:

Research published in the European Journal of Cancer shows the UK has the worst survival rates for cancer in western Europe, with rates one third lower than those of Sweden. UK cancer survival worst in western Europe, 'Daily Telegraph', 26 September
The article gives examples:

Five-year breast cancer survival was 79.1 per cent in England, 78.5 per cent in Scotland, and 78.2 per cent in Wales. In Sweden the figure is 86 per cent, with an European average of 81.8 per cent. In England, 80.3 per cent of men with prostate cancer were alive five years later, compared with 90.2 per cent in Austria, 90 per cent in Finland and a European average of 83.4 per cent.
At first glance, this seems an indictment of the UK's approach to diagnosing and treating cancer. But the five-year survival rate needs interpretation: it is the proportion of patients still living five years after diagnosis. We can improve the five-year survival rate by better treatment, which is unambiguously good, or by earlier diagnosis, which is far more questionable. Earlier diagnosis can simply mean more intervention and more treatment (and more side effects), but does not necessarily lead to a reduction in the cancer mortality rate - which is a far better indicator of healthcare efficiency than the five-year survival rate.

A Social Policy Bond regime aiming at improving the overall health of a population would refine and target more-robust indicators, such as mortality and longevity, and would do so impartially. For more about Health Bonds, click here. For more about how misleading are five-year survival rates click here or here.

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