An NHS scheme to drive integration between health and social care has not delivered the transformation of services originally planned, an official report has found.
Much of the funding intended for the "vanguard" programme was diverted to relieve short-term financial pressures in the health service, the National Audit Office (NAO) said.
The scheme has not been expanded across England as initially hoped as a result, according to the report.
NHS England selected 50 sites to pilot new models to deliver health and social care as part of its five-year plan, published in 2014.
They were tasked with designing new care models - for example, integrating GP, hospital and community and mental health services - which could be replicated across England.
About £329 million has been invested in the sites since 2015, as well as an additional £60 million spent by NHS England on central support.
However, the NAO said much of the funding intended for the programme was used to reduce hospital deficits.
The report said: "The vanguard programme is one in a series of attempts to transform the NHS to better meet patients' needs and to respond to the financial pressures it faces.
"However, short-term financial pressures led to the diversion of much of the transformation funding, weakening the programme's chances of success."
It added: "An important objective of the programme was to design new care models that could be replicated quickly across the NHS and services have not yet been transformed to the depth and scale that was hoped for at the beginning of the programme."
NHS England chief executive Simon Stevens has confirmed it will "sustain and spread the vanguard new care models through a long-term plan", the report said.
It added: "We look forward to seeing this carried through, so that NHS England breaks out of previous cycles of missed opportunity and delivers full value for money."
Amyas Morse (pictured), head of the NAO, said: "The vanguard programme is one of a series of attempts to transform the NHS. Its progress has been mixed but there are some early signs of a positive impact.
"I am pleased that the chief executive of the NHS has confirmed to us his commitment to sustaining and spreading vanguard new care models through a long-term plan, and hope that NHS England can break out of previous cycles of missed opportunity."
Some hospitals in vanguard areas have seen a positive impact on the number of emergency admissions but it is too soon to fully assess their impact, the report said.
A spokesman for NHS England said: "The NAO rightly highlights the success of the vanguard sites, both in improved outcomes for patients through fewer emergency admissions, and value for money with an expected return of £2 for every £1 spent.
"It is now crucial to build upon this progress as the NHS develops its 10-year plan."
Copyright (c) Press Association Ltd. 2018, All Rights Reserved. Picture (c) National Audit Office.