Karen B. Lasater, PhD, RN, FAAN

Associate Professor of Nursing

Nurses are the frontline providers of health care, and as such, are well-positioned to influence patient outcomes.

Dr. Lasater is a nationally recognized researcher who uses state of the science methods to explicate the value of nurses and establish the business-case for investing in hospital nursing. Her research identifies how the institutional environments where nurses deliver health care and the policies governing them, impact patient outcomes with a particular focus on patient outcomes that represent complex healthcare challenges.

Nurses are essential to addressing complex health care challenges that are salient to patients and their families.


  • PhD, University of Pennsylvania, 2015
  • MS, University of Pennsylvania, 2013
  • BSN, Quinnipiac University, 2010


Dr. Lasater leads the introductory statistics course for undergraduate nursing students, NURS 2300: Statistics for Research and Measurement, teaching that mastery of the fundamentals of statistics is a powerful tool for improving health outcomes. She has received the Anne Keane Teaching Award from the Department of Biobehavioral Health Sciences (2020) and the Undergraduate Award for Teaching from the Student Nurses at Penn (SNAP, 2022).


Decades of research demonstrate that patients have better clinical outcomes of all kinds, including lower odds of dying, when cared for by nurses responsible for fewer patients at a time. Despite the evidence, there remains considerable variation in hospital nurse staffing practices, with negative consequences to patients’ health. Often discussed, but rarely implemented due to a lack of local and recent evidence about whether it is in the public interest, is safe nurse staffing legislation. In a creative partnership with the National Council of State Boards of Nursing, Dr. Lasater leads a unique major initiative to rapidly produce evidence about the hospital nurse-to-patient staffing ratios and its association with patient outcomes – information needed to inform policy choices in states considering staffing legislation. This study brings rigorous, current, relevant evidence—collected prior to implementation—to policy discussions impacting the public’s health and healthcare.

Dr. Lasater’s work on the value of nursing is generating a new line of evidence on the economic impacts of staffing decisions. Using state-of-the-science methods in nursing outcomes research that enable patients to be exact-matched for risks, her research demonstrates that patients in hospitals with better nurse resources experience better outcomes (lower mortality, fewer complications, fewer readmissions, shorter lengths of stay), with no difference in costs. The demonstration of better patient outcomes with improved nurse resources is now providing institutions with the evidence needed to adopt evidence-based nurse staffing and improve work environments. Framing results in a business-case for nursing is a powerful motivator. Dr. Lasater’s research shows that the costs of improved staffing can largely be offset through cost savings associated with shorter lengths of stay and avoided readmissions.

Opportunities to Learn and Collaborate at Penn Nursing

Dr. Lasater is a Senior Fellow of the Leonard Davis Institute of Health Economics – a world-renowned intellectual hub of health-systems research and policy. Through this integrated network of leading health systems and policy researchers, she has worked with scholars across disciplines, including medicine, economics, demography, and statistics. She is a Research Associate at the Population Aging Research Center (PARC).

Selected Career Highlights

  • Fellow of the American Academy of Nursing
  • Senior Fellow, Leonard Davis Institute of Health Economics
  • Undergraduate Award for Teaching from the Student Nurses at Penn, SNAP, 2022
  • New Investigator Award, AcademyHealth Interdisciplinary Research Group on Nursing Issues, 2019

Featured Publications

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