Minnesota-based Fairview Health Services suffered a net loss of $114 million in 2008, largely because of investment losses and higher interest rates on debt, according to unaudited numbers. Even without investment losses, the chain of hospitals and clinics had a tough year because of fewer inpatient visits and more unpaid medical bills. Net operating income was $20.8 million, down 57% from 2007. That translated to an operating margin of just 0.8%, compared with 2.1% in 2007.