Portland hospitals, for the most part, enjoyed a good year in 2015, with operating margins in positive territory. There was one exception: Tuality Healthcare, with a margin of about -0.3 percent. Otherwise, returns ranged from 1 percent at Providence Portland Medical Center to nearly 13 percent at Legacy Meridian Park Medical Center. The median return, at 4.7 percent, exceeded the 3.4 percent median for U.S.