Intended for healthcare professionals

Rapid response to:


Predicting risk of type 2 diabetes in England and Wales: prospective derivation and validation of QDScore

BMJ 2009; 338 doi: (Published 18 March 2009) Cite this as: BMJ 2009;338:b880

Rapid Response:

Statistical risk- is it applicable to an individual?

Trying out my own data on the risk calculator (I had to lie about my
age) produced a 10 x 10 table of smileys- 13 of which had frowns, placed
at random in the 100 squares. I think this is a well meaning, but doomed,
attempt to transfer a legitimate statistical interpretation, ie of a large
number of people, to the risk of an event to an individual. This hooker
has been recognised for years, and no one has solved it. There is also
Hume's problem: there can be no certainty that what happened under certain
circumstances in the past will happen again in the future ( a mantra much
employed by financial advisers.) The changing risks associated with the
Framingham equation over the years and in different places testify to the
truth of this. Finally, we dont know either whether ameliorative measures
will work (unless you already know the glucose tolerance) nor at what risk
level they might usefully be employed.

All this is a pity because the study per se is jolly good!

Competing interests:
None declared

Competing interests: No competing interests

06 April 2009
Harry Hall
Retired physician