The routine use of scans in patients with lower back pain does not improve their outcomes, US scientists say.

Imaging in the first month of low back pain is not recommended in the US or in draft guidelines of National Institute for Clinical Excellence (NICE). UK.

Researchers looked at six trials including more than 1,800 patients and found no benefit from the scans when patients were followed for up to a year.

Previous studies in the UK have shown similar results.

The researchers said the results were most applicable to the type of acute lower back pain assessed by a general practitioner.

They looked at pain, function, quality of life, mental health, overall patient-reported improvement and patient satisfaction in the care they received for up to a year after their initial treatment.

All the patients were randomised to receive either immediate scans or standard clinical care.

Some of the standard care group were offered scans if they had not improved within three weeks.

They did not find significant differences between immediate imaging with X-ray or MRI scans and usual clinical care either in the short-term - up to three months later, or the long-term - six to 12 months.

Dr Roger Chou, lead researcher from the Oregon Health and Science University said some doctors still do it routinely, "possibly because they aim to reassure their patients and themselves, to meet patient expectations about tests or because reimbursement structures provide financial incentives to image".