Astria Health, an operator of three hospitals and dozens of outpatient clinics, filed for bankruptcy Monday, saying the outsourcing of its collection work has been mired in problems and has led to a cash crunch. The nonprofit regional health-care system, which is based in Sunnyside, Wash., and generates $240 million in annual revenue, sought protection from creditors in U.S. Bankruptcy Court of Spokane and Yakima, owing more than $160 million in debt.