There were at least 124 cases of medical malpractice reported by public hospitals in fiscal 2002, up 31 from the previous year, according to a health ministry file released Tuesday.

Many of the incidents involved simple human error, including medicine overdoses or leaving surgical instruments in patients' bodies, the file says. It includes reports to the Health, Labor and Welfare Ministry on malpractice at public medical institutions across Japan.

The rise in the number of cases since fiscal 2001, when the report system was launched, indicates better awareness of problems on the part of officials at the institutions, instead of an actual increase, a ministry official said. The reported cases include those in which the institutions admit negligence and those in which they deny it.

One of the cases is an incident at Tokyo Disaster Medical Center in which a doctor performed plastic surgery on the wrong side of a patient.

In another case, a needle was left inside a patient at the National Cardiovascular Center in Osaka Prefecture.

Transfusions of the wrong blood type were reported at hospitals in Hakodate, Hokkaido, and Shimonoseki, Yamaguchi Prefecture. Intestinal punctures during endoscopy procedures were reported at hospitals in Yokaichi, Shiga Prefecture; Iwakuni, Yamaguchi Prefecture; and Oita.

The file does not say whether any of the cases resulted in death.