State employee Jan Mathews switched from Cigna to BlueCross for health insurance last year to save money on premiums. This year she plans to switch back, to avoid paying more to use The Women's Hospital at Centennial Medical Center. "They're just known for having exceptional health services for women, and my OB/GYN is there," Mathews said. TriStar Health System hopes more state employees will make the same choice. The local HCA unit, which includes The Women's Hospital and eight others, doesn't participate in BlueCross' Network S, offered to state workers and early retirees.