It scarcely seemed plausible 18 months ago that a few modest changes to raise standards and reduce errors in hospitals could stave off such a large number of patient deaths or that enough hospitals would voluntarily make the changes. But last week, as the "100,000 Lives Campaign" came to a close, Donald Berwick, the plan's architect, triumphantly informed medical quality experts meeting in Atlanta that an estimated 122,000 patient deaths had been avoided. In a normal year, about 1 million hospital inpatients die from all causes.

Berwick's Institute for Healthcare Improvement in Cambridge, Mass., the think tank that drew up the plan, had hoped 2,000 of the nation's roughly 6,000 hospitals would cooperate, but more than 3,000 signed on. "It gave them something demonstrable they could do at relatively little cost that was easy for the medical staff to accept and easy for their local communities to understand," says Rick Wade of the American Hospital Association.

Six easy pieces. The half-dozen elements of the program targeted maximum impact and low cost and disruption. Two examples: creating "rapid response" teams that quickly evaluate any patient whose condition troubles a caregiver even without an obvious reason, and reducing surgical infections by timing antibiotic use. Only about 40 percent of the hospitals embraced all six changes; Berwick's next goal is to get to full participation. The figure of 122,000 is a good-faith estimate, says Berwick. It compares each hospital's deaths during the campaign, month by month, with deaths in the same month of 2004, adjusting somewhat for variation in patients' condition.

If Berwick wants a new challenge, emergency care would qualify. Last week the Institute of Medicine released three pessimistic reports. With more patients but fewer emergency departments and hospital beds, patients are being "boarded"--held in hallways or wherever there's room, sometimes for days, until a bed opens up--and diverted to other hospitals because of overcrowding. And in the event of a calamity like a massive flu outbreak or natural disaster, warned the IOM, many emergency departments would quickly be overwhelmed--snuffing out some of the very lives hospitals are trying to save.