One of every seven Medicare beneficiaries who is hospitalized is harmed as a result of problems with the medical care there, according to a new study from the Office of Inspector General for the Department of Health and Human Services.

The study said unexpected adverse events added at least $4.4 billion a year to government health costs and contributed to the deaths of about 180,000 patients a year.

In a single month, October 2008, the report estimated that some 134,000 Medicare patients experienced at least one adverse event, ranging from a temporary health setback to death, during a hospital stay. It said 44 percent of them were ‘clearly or likely preventable.