Indianapolis-area hospitals have invested more than $1 billion to build new facilities since 2000, as well as invested in new outpatient surgery centers and specialty facilities. The hospitals have also started for-profit arms that rake in millions. The building binge is driving up the revenues of some of the hospitals, but it also is exacerbating differences in the financial health of the region’s four major hospital systems: St. Francis, St. Vincent, Clarian Health and Community Health Network.