The clinical advances of the last fifty years have led to dramatic increases in life expectancy, and years of life free from disability. However, there are still five outstanding problems in every health service: patient harm, waste, unwarranted variation in outcome, inequity, and failure to prevent the preventable. Furthermore, every health service also has to face the four new challenges: rising demand and increasing need, which have to be met within both financial and carbon resource constraints. What is needed is new ways of improving the value of the services provided for patients and populations by harnessing the one resource that increases the more it is used - knowledge. Already there are seven knowledge businesses based in the Oxford centre for healthcare transformation -