I have had a few emails over the last few months about using QOF data for research and trying to break down some of the data. Unfortunately QOF is quite limited in what can be divined about individual patient treatment. There is a little more potential for breaking down populations with some of the composite registers this year but things are still pretty limited.
For those looking at used primary care data there is an excellent report on all of the sources of primary care data available. A user’s guide to data collected in primary care in England is a summary of all of the data sources, including QOF, with details of their uses and limitations. It is published by the Eastern Region Public Health Laboratory - one of the rather unsung chain of public health laboratories.
This has to be essential reading for anyone conducting or even contemplating doing research or analysis on primary care data. I can't actually see that a printed version is available or I would get a copy for my bookshelf - but get it on your computer now!