Back pain is costing the UK one million years of lost productivity each year in part because GPs are signing patients off work too easily, a major new study has found.

Medical leaders have condemned the “unconscionable” readiness of doctors to prescribe rest, painkillers and to order intrusive tests when many patients should instead be advised to keep active.

The findings are published in a series of Lancet studies which names lower back pain as the leading cause of disability in the world.

The global burden of disability it causes has risen by more than 50 per cent since 1990, the research found.

Most cases of lower back pain respond to simple physical and psychological therapies aimed at keeping people active and able to stay in work.

However, medics routinely ignore their own guidelines and order surgery or scans instead of giving education and advice, according to the research.

“Millions of people across the world are getting the wrong care for low back pain,” said lead author Professor Jan Hartvigsen, from the University of Southern Denmark.

“Funders should pay only for high-value care - stop funding ineffective or harmful tests and treatments and, importantly, intensify research into prevention, better tests and better treatments.”