LONDON About five percent of patients suffer an illness or injury while in hospital, costing the state-funded National Health Service at least one billion pounds ($1.4 billion) a year, doctors said on Friday.

A pilot study, the first of its kind in Britain, estimates that just under 500,000 people admitted to hospitals in England and Wales pick up an infection or are injured during care.

Half of the so-called adverse events are preventable and a third lead to moderate or serious disability and death.

"Adverse events are a major source of harm to patients and a major drain on National Health Service resources," said Professor Charles Vincent of University College London, one of the authors of the study.

Wound infections, bed sores, early discharge and adverse drug reactions were among the most common problems. Hemorrhaging and complications during surgery were among the most serious.

"We estimated that for each adverse event people, on average, had to stay about a week extra in hospital. That in itself is no big deal. It often happens but when you add it up we came to a figure of a billion pounds a year, just in the costs of keeping people in hospital," Vincent added in a telephone interview.

But the figure is likely to be higher because the pilot study did not take into account what happens in primary care, or mental health care or the costs of legal action.

"This is the first time a study of this kind has been done in the UK," said Vincent.

An American study found that 3.7 percent of U.S. hospital admissions led to adverse events. In Australia it was as high as 16 percent and estimated to cost the equivalent of 1.8 billion pounds ($2.6 billion).

"We have as big a problem as other countries do but we haven't recognized the full scale of costs of this and we should do a substantial study to get to grips with it," said Vincent.

"The cost of the survey would be equivalent to the money lost through preventable adverse events in less than eight hours in the NHS."

Vincent and his team reviewed 1,014 surgical, geriatric, general medicine, orthopedic and obstetric records from 1999-2000 from the two hospitals.

Nearly 11 percent of patients in the study had suffered an adverse event. Most of them occurred in wards and with discharge arrangements, the researchers said. Many could be have been avoided through procedural changes.

(Reuter)