All the big-picture policy talk about controlling the cost of healthcare runs smack into the real world at the hospital nursing station. This is true across the country, but especially in Massachusetts, where nurses are pressing several hospitals in contract talks. Two negotiations in particular—at Tufts Medical Center in Boston and St. Vincent Hospital in Worcester—are focused on staffing levels for nurses. Hospital administrators say they are trying to manage in challenging times, reorganizing work to become more efficient while maintaining the quality of care. Many nurses and their union say the practical result of efficiency plans is a thin staff that put patients at greater risk.