The National Health Service (NHS) is the umbrella term for the publicly funded healthcare systems of the United Kingdom (UK). Since 1948, they have been funded out of general taxation. There are three systems which are referred to using the "NHS" name (the NHS in England, NHS Scotland and NHS Wales). Health and Social Care in Northern Ireland was created separately and is often locally referred to as "the NHS". The four systems were established in 1948 as part of major social reforms following the Second World War. The founding principles were that services should be comprehensive, universal and free at the point of delivery—a health service based on clinical need, not ability to pay. Each service provides a comprehensive range of health services, free at the point of use for people ordinarily resident in the United Kingdom apart from dental treatment and optical care. In England, NHS patients have to pay prescription charges; some, such as those aged over 60 and certain state benefit recipients, are exempt.Taken together, the four National Health Services in 2015–2016 employed around 1.6 million people with a combined budget of £136.7 billion. In 2014, the total health sector workforce across the United Kingdom was 2,165,043. This broke down into 1,789,586 in England, 198,368 in Scotland, 110,292 in Wales and 66,797 in Northern Ireland. In 2017, there were 691,000 nurses registered in the United Kingdom, down 1,783 from the previous year. However, this is the first time nursing numbers have fallen since 2008. Every 24 hours it sees one million patients, and with 1.7 million staff it is the fifth biggest employer in the world, as well as the largest non-military public organisation in the world.When purchasing drugs, the four healthcare services have significant market power that, based on their own assessment of the fair value of the drugs, influences the global price, typically keeping prices lower. A small number of products are procured jointly by two or more UK healthcare services. Several other countries either copy the United Kingdom’s model or directly rely on Britain’s assessments for their own decisions on state-financed drug reimbursements.