A survey of health care facilities found that 85% had used temporary doctors in the past year to fill in gaps caused by a national shortage of physicians. “Virtually every hospital in the United States now uses locum tenens doctors [temporary physicians],” said Jeff Decker, president of Staff Care, the health care staffing firm that conducted the survey. “They have emerged as a key part of the medical workforce in an era of physician shortages and evolving delivery models.”