An investigation into hospital charges in the United States has revealed that uninsured patients are charged more than three times than those who are insured.

The two-year study, appearing in the May issue of the journal Health Affairs, examined hospital charges between 1984 and 2004 and found that hospital patients without health insurance and others who pay for medical care out of their own pockets were charged an average 2.57 times more than those with health insurance. New Jersey and Pennsylvania had the highest markups.

San Francisco Chronicle quotes Gerard Anderson, director of the Center for Hospital Finance and Management at Johns Hopkins Bloomberg School of Public Health as saying, "The hospitals have to drop their charges to a reasonable amount for everybody."

The report also adds that the number has been rising steadily since 1984, but has jumped more quickly since 2000. However, the lowest markup rates were in Idaho, Maryland, Montana Vermont, and Wyoming (less than two times of Medicare-allowable costs).

Rebuking the charges, the hospital industry says the report is three years old and since then many hospitals have changed their billing practices. In addition, California enacted a law to curb hospital charges to uninsured patients, where hospitals can charge low- to moderate-income patients no more than the highest rates charged by Medicare or any other government payment program in which the hospital participates.

The study also found that for-profit hospitals had the highest discrepancy between costs estimated by Medicare and prices charged. More than 60 class-action lawsuits have been filed against U.S. hospitals over the fee issue.