More than £12 million has been spent by the NHS in England on collecting feedback from patients for a test with a "questionable measure of performance," health experts have said.
Arguing that the Friends and Family Test (FFT) should no longer be mandatory, Glenn Robert, Professor of health care quality and innovation at King's College London, said there was "widespread unease" about it among staff.
The test, which was introduced in all acute hospitals in England in April 2013 to highlight both good and poor patient experience, can be seen as "purely a tool for national bodies to monitor them," he wrote in the BMJ.
The FFT has seen more than 30 million pieces of feedback collected, with a further million added each month, which makes it the biggest source of patient opinion in the world, according to NHS England.
However, Prof Robert and his colleagues said collecting and managing such large amounts of data is complex, requiring substantial investments of time and other limited resources.
Although expenditure has decreased, it still cost about £1.5 million in 2016/17, they said.
By making it non-mandatory, "NHS England could free up the time and resources that providers currently spend on metrics that provide little insight for practitioners".
The case for a compulsory friends and family test "lacks a strong rationale and scientific evidence", they argued.
They added that continuing with the test "risks displacing more fruitful approaches to patient feedback that are more likely to engage clinicians".
The NHS should stop making its organisations "collect large amounts of data of unknown representativeness with poor response rates that provide little insight," they concluded.
Dr Neil Churchill, NHS England's Director for Patient Experience, said: "More than half of NHS staff say they use this patient feedback to improve services to patients and in a recent survey 88 per cent of trusts said FFT was working well and 78 per cent said it had increased their emphasis on patient experience."