Hospitals with the most nurses from overseas have the worst ratings from patients, a major study has found.

Experts behind the research–the first study of its kind–showed that an increasing reliance on nurses trained abroad could be damaging the quality of care on the wards.

Amid growing shortages of nurses across the country, the number coming here to register for work after training abroad has almost doubled in two years.

The new study found that hospitals with the highest proportion of foreign nurses had the highest levels of patient dissatisfaction, with patients more likely to say they struggled to understand staff, and less likely to feel treated with dignity.

The study by Kings College London and the University of Southampton examined the workforce of 46 NHS hospitals and surveyed 12,000 patients.

At some hospitals, more than half of nurses were trained abroad, the research found, most commonly from the Philippines, India and countries in Africa.

For every 10 per cent increase in the number of nurses who trained abroad, there was a 12 per cent decrease in the likelihood of patients rating their hospital good or excellent, the study found.

There was also a 14 per cent drop in whether patients felt they could easily understand staff, a 10 per cent drop in whether medication had been explained to them, while patients were 8 per cent less likely to feel treated with dignity and respect.

Latest figures show that between 2012/13 and 2014/15, the number of nurses who trained abroad and joined the register to work in the UK rose from 4,305 to 8,183.

NHS trusts have been attempting to recruit more nurses in response to the Mid Staffs scandal, where staff shortages contributed towards appalling failings in care.

Last week the Chancellor announced plans for 10,000 more nurse training places.

But the changes will see the introduction of tuition fees and loans, which could mean a student debt of up to £65,000, raising fears they could deter new recruits.

The new study, published in the journal BMJ Open found that the proportion of nurses trained overseas was “significantly” linked to how patients felt about their care.

The study concludes: “Use of non-UK educated nurses in English NHS hospitals is associated with lower patient satisfaction. Importing nurses from abroad to substitute for domestically-educated nurses may negatively impact quality of care.”

Researchers suggested that language barriers, and different expectations about what the job of a nurse involves could be having an impact.

It cites studies which found nurses educated in developing countries were more likely to spend time doing chores such as cleaning and to spend less time talking to patients about their health.

In the 31 trusts, covering 46 hospitals, 30 per cent of overseas nurses came from the Philippines, with 24 per cent from India and 19 per cent from countries in Africa.

Professor Anne Marie Rafferty, study co-author from King’s College London, said: “Language differences, cultural expectations, and professional norms of different countries may all contribute to patients’ perceptions and create challenges for rapid and effective decision-making for acutely ill hospitalised patients.”

Co-author, Professor Peter Griffiths, said the study showed how important it was to boost the domestic supply of nurses, and to give more support to those who came here from abroad.

“Relying on bringing in large numbers of foreign educated nurses to make up the shortfall is not a simple solution and may not be effective,” said Prof Griffiths, chairman of health services research at the University of Southampton.

A Department of Health spokesperson said: “Overseas nurses are a crucial part of the NHS team but they must be highly qualified, demonstrate care and compassion and have good communication skills. The Nursing and Midwifery Council has strict criteria to make sure this is the case.

“We know that well supported staff provide better care to patients and this includes making sure we have the right number of staff. The aim of our plans set out in the Spending Review is to increase the number of additional home-grown nurses we have in our hospitals–we expect 23,000 more by 2020.”