Wired on Friday: The very critical issues of medical errors and patient safety have received a great deal of attention. In a November 1999 report, To Err Is Human, the Institute of Medicine, a research panel affiliated with the National Academy of Sciences, found as many as 98,000 Americans die each year as a result of medical errors in hospitals. This is more than die from motor vehicle accidents, breast cancer or AIDS.

Medication errors alone are estimated to account for over 7,000 deaths each year and about 770,000 injuries. As part of a wide-ranging effort to improve patient safety, in February this year, the Food and Drug Administration finalised a rule requiring bar codes on the labels of thousands of human drugs and biological products.

The rule also requires machine-readable information on container labels of blood and blood components intended for transfusion.

The FDA estimates it will help prevent nearly 500,000 adverse events and transfusion errors while saving $93 billion over 20 years.

"Bar codes can help doctors, nurses and hospitals make sure that they give their patients the right drugs at the appropriate dosage," health and human services secretary Mr Tommy Thompson said.

Each bar code will contain the drug's national drug-code number. This will be encoded on the label of the product. Companies also may include lot numbers and expiration dates.

The bar-code rule is designed to encourage widespread adoption of advanced information systems that, in some hospitals, have reduced medication error rates by as much as 85 per cent.

In a study conducted at a Veterans Affairs Medical Center employing the system, 5.7 million doses of medication were administered with no errors. The FDA first proposed bar-code requirements in March 2003. A few pharmaceutical companies and about 300 hospitals have begun using bar codes.

Hospitals that use such systems give patients a bar-coded identification bracelet when they are admitted to the hospital. Before a healthcare worker administers a drug to the patient, he scans the patient's bar code with a hand-held scanner that is linked to the hospital's computer system.

The computer then compares the patient's medical record to the drug being administered. If there is a problem, the computer sends an error message.

One of about 12 companies nationally that sell bar-code software is Bridge Medical, an Amerisource Bergen company based in California.

It has 32 hospitals using its Microsoft-based software, which is device-independent, and it has sold 90 contracts. Ms Denean Rivera, president of Bridge Medical, said: "Medical errors cost the healthcare industry millions of dollars in additional treatment, extended stay, malpractice and litigation lawsuits."

One hospital that is going a step further is Georgetown University Hospital in Washington DC. It is testing a combination of bar code and radio-frequency identification chip (RFID) for extra security.

Dr Gerald Sandler, professor of medicine and pathology and director of transfusion medicine at Georgetown University Hospital, said: "We are probably the only hospital in the world with both a radio-frequency chip and bar-code scanner in one reader." The hospital has researched bar-code technology for the past five years.

It has experimented with three different systems. The first company withdrew from the market. The second was Bridge Medical. "Such a system was well accepted by the nurses as an improved way of identifying patients and blood products," Dr Sandler said. "But, they didn't use it often enough... to feel confident and proficient when using it." The set-up cost would have been $1 million which, Dr Sandler said, was a "way-out-of- range capital expense for us."

The other drawback was that the longer a patient stayed in the hospital the grubbier his bar-code wrist bracelet became.

The third and current company the hospital is working with is Precision Dynamics in San Fernando, California, which puts radio-frequency chips into bar-coded wristbands and protects them with plastic.

"This provides us with an instantaneous fallback situation," Dr Sandler said. "If the nurse... comes in touch with a worn band, she can flip on this device and it will back up the information."

The hospital is only using RFID in patients who are getting blood transfusions, which has been fewer than 25 patients so far, in which, Dr Sandler said, it has proved to be 100 per cent accurate.