Just a third of staff at Gloucestershire Health and Care NHS Trust are doctors or nurses, new figures show.

A think tank said the recent expansion of non-medical roles in the NHS has come before "significant issues have been addressed".

In a new report commissioned by NHS Employers, health and social care think tank Nuffield Trust highlighted how the NHS has introduced different roles into the workforce, including physician associates, nursing associates and advanced nurse practitioners.

The report urged the health service to heed lessons from history, and called for a "proactive approach" to address challenges and prevent "negative consequences" for patients, staff and productivity.

The latest NHS England figures show there were 4,118 full-time equivalent staff at Gloucestershire Health and Care NHS Foundation Trust as of September, including 128 FTE doctors and 1,268 FTE nurses and health visitors.

It means just 34% of the trust's FTE staff were doctors or nurses.

The type of trust – whether it's an acute hospital trust, mental health trust or community health trust, for instance – can influence its workforce composition.

Further analysis from the Nuffield Trust shows doctors and nurses across England accounted for just 39% of the workforce, which was the lowest proportion of all the OECD countries.

In November, the Government launched a review into the role of physician associates and those working in anaesthesia after concerns were raised about patient safety.

Under current workforce plans, there could be 14 times more nursing associates by 2036-37, with around six times more physician associates and anaesthesia associates.

William Pett, head of policy and public affairs at health and social care campaign group Healthwatch, warned changes to the NHS workforce, including the expansion of roles such as physician associates, means patients do not always understand what each healthcare professional does and who exactly they are receiving care from.

He said: "When new staff are directly involved in providing care, they must make their roles and responsibilities clear to patients.

"Those planning changes in our healthcare workforce should closely engage with patients to make sure that new roles are established and deployed in ways that best meet their needs."

Commenting on the report, Nuffield Trust senior policy fellow Dr Billy Palmer said the future expansion of the NHS workforce "rests heavily on new and emerging roles", which will bring "big challenges" such as ensuring existing staff can oversee new recruits adequately.

Dr Palmer said: "These challenges can be overcome with careful planning, time and attention at all levels in the health system, but the NHS must take heed of the well-established lessons from history.

"The Government’s review of physician and anaesthesia associates, and its wider refresh of the long-term workforce plan provide an important opportunity to set out some clarity over the transition and avoid further repeating the mistakes of the past."

Caroline Waterfield, director of development and employment at NHS Employers, said it is "critical" the report’s findings are central to NHS England’s workforce plan.

A Department of Health and Social Care spokesperson said: "This Government will overhaul the NHS to make it fit for the future, moving more care from hospitals and into the community.

"This summer, we will publish a refreshed workforce plan to ensure we have the staff we need so that patients are cared for by the right professional, when and where they need it.

"We are taking decisive action to transform the NHS and get it treating patients on time again."