NHS Providers, the body that represents trusts, says several factors, including A&E waiting times and staff shortages, suggest problems for hospitals in the months ahead.
At Doncaster and Bassetlaw Teaching Hospitals NHS Foundation Trust, A&E waiting times have improved since last year, with 92 per cent of patients now being admitted, transferred or discharged within four hours, up from 90 per cent at the time in 2017.
However, this is still below the Government’s target of 95 per cent.
Across England, the percentage of people dealt with within the time limit dropped by one per cent since last year, to 84 per cent in 2018.
NHS Providers believes this indicates the coming winter is likely to put more strain on trusts than the last.
Saffron Cordery, NHS Providers deputy chief executive, said: “Trusts and their staff put in extraordinary efforts last year to meet record demand - demand which continues to grow every winter.
“Despite measures to prioritise emergency care, it was clear that in many places the quality of care for patients feels short of what the public rightly expects.
“As attention turns to what this winter will bring, there are many improvements which have been put in place to welcome.
“But there are clear warning signs.
“Performance is in a worse position going into this winter than last. Staff shortages are growing, putting additional strain on a workforce already overstretched during an exceptionally busy summer.”
The situation is compounded by a number of unfilled roles at Doncaster and Bassetlaw Teaching Hospitals NHS Foundation Trust.
In March 2018, the most recent period for which data is available, there were vacancies equivalent to 84 full time jobs, compared with 65 in April 2017.
Of those, 29 were nurses and 15 were other medical staff.
And NHS Digital has warned that the number of nurse vacancies was likely to be higher, as the figures show the minimum number of jobs advertised, and many trusts have rolling adverts for nurses.
Donna Kinnair, acting chief executive and general secretary of the Royal College of Nursing, said: “Staff are doing all they can, but demand is outstripping supply and winter 2018 could be the one that brings services to a standstill.
“The signs in the Providers’ report are ominous - increasing demand, worsening A&E performance and a yawning chasm in nurse numbers.
“Despite our warnings, the Government has still not acted to fill the 41,000 nurse vacancies in England alone.
“This means we go into winter with understaffed services, gaps in hospital rotas and a workforce that is more under pressure than ever.
“Staff across England have given almost all they can - nurses tell us they cannot keep this up indefinitely.”
The NHS Providers report calls on NHS national bodies to acknowledge and plan for the scale of extra, more complex demand that health and care services face.
A spokesman for the Department of Health and Social Care said: “We recognise winter can be challenging, but as the report itself notes, the NHS will benefit from a second year of better, enhanced, national level winter planning, as well as £420 million to redevelop A&Es, improve emergency care and help get patients home quicker.
“The most recent performance statistics show that despite an increase in demand, hardworking and dedicated staff ensured that nearly 2,000 more patients a day were seen within four hours in September compared to the same month in 2017.”