The number of bankruptcies tied to medical costs in the United State is on the rise.

A Harvard University study out today shows a 50 percent increase in such bankruptcies between 2001 and 2007. The vast majority of the 2,300 bankruptcy filers surveyed had health insurance when their medical problems began.

Study co-author Steffie Woolhandler, an associate professor of medicine at Harvard, spoke with WBUR’s Delores Handy about the findings.