As the nation celebrates the 70th birthday of the NHS, many of us will undoubtedly have good reason to say thank you for its help at some point in our lives.

So perhaps it no surprise that Theresa May has announced the extra £20bn to keep the NHS going. It is undoubtedly a popular decision. However there remains a question about whether this is the best use of increasingly scarce public funds if our goal is to improve the health of the nation.