Linda Aiken, PhD, RN, is an authority on causes, consequences, and solutions for nurse shortages in the U.S. and internationally. Dr. Aiken directs the Center for Health Outcomes and Policy Research at Penn Nursing, and her research findings on staffing and mortality are frequent references in ongoing policy debates about patient-nurse ratios. More than 20 states now have legislation enacted or pending because of her work. Dr. Aiken leads the International Hospital Outcomes Consortium studying the impact of nursing on patient outcomes in 13 countries.