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Generating evidence on nursing and better outcomes for all.

Nurses4All, a project initiated by the University of Pennsylvania’s Center for Health Outcomes and Policy Research, is the most extensive and long-standing survey focused on nurses and their working conditions. The initiative, funded by the National Institutes of Health, has produced compelling evidence emphasizing the importance of adequate staffing and favorable work environments for nurses. The insights gathered also serve as valuable resources for building a practical business case to advocate for increased investments in nursing.


In 2023 and 2025-26, we’ll replicate surveys conducted in 1999, 2006, 2016, 2020, and 2021 in eight states (CA, FL, IL, LA, NJ, NM, NY, PA), representing 40%+ of national nurses. This study explores how changes in nursing resources (environment, staffing, education) influence patient outcomes across settings (hospitals, clinics, schools). By assessing nurse and patient data, we’ll gauge nursing’s impact on outcomes over time. Insights will guide transformative interventions for equity, nurse well-being, and patient results.


Thank you for your involvement in the Nurses4All study. Your contributions have been vital to the success in advancing scientific knowledge and nursing workforce improvements. Please access the Nurses4All FAQs for more information.


CHOPR’s efforts have initiated policy shifts benefiting nurses and enhancing patient care and outcomes nationwide and globally. Explore the impact areas below to delve into the diverse ways our work has shaped nursing across different nursing dimensions.


Nurse Staffing
CHOPR’s significant research establishes a strong connection between nurse staffing ratios and patient outcomes. Our findings demonstrate that higher patient-to-nurse ratios lead to increased mortality, longer hospital stays, and more readmissions. This evidence has influenced nurse staffing legislation in various US states (CA, MA, NY, IL, OR) and globally (Chile, Wales, Queensland), and most recently played a central role in Pennsylvania’s Patient Safety Act. Over two decades, CHOPR’s work has consistently driven policy changes for better patient care.
Nurse Work Environment and Magnet®

Our research shows improved nurse work environments link to safer, high-quality care and lower hospital costs. The Practice Environment Scale of the Nursing Work Index, developed at CHOPR, has been validated and used to measure hospital work environments globally since 2002. Our work contributed to ANCC Magnet Recognition Program®, indicating patients in Magnet hospitals experience better outcomes, higher care quality, enhanced patient satisfaction, and improved nurse outcomes.

Clinician Wellbeing and Nurse Outcomes
Our research indicates nurses face burnout in hospitals with high patient-to-nurse ratios and poor work environments. Following the National Academy of Medicine’s recent landmark report on clinician burnout, CHOPR led the first U.S. study affirming the benefits of positive work environments and sufficient nurse staffing on clinician wellbeing, encompassing burnout, mental health, job satisfaction, and turnover.
Nurse Practitioners & Ambulatory Care
Our research strongly links nurse practitioner care, especially in primary care settings, to patient outcomes. CHOPR’s findings show that supportive clinical environments lead to improved chronic disease management, patient-centered care, and fewer hospitalizations, particularly benefiting marginalized and low-income patients. We’re also exploring registered nurses’ impact on patient outcomes in ambulatory care.
Aiken et al. (2011) discovered that having 10% more nurses with Bachelor of Science in Nursing Degrees reduces patient mortality and failure to rescue odds by about 4% across hospitals, regardless of the work environment quality. Similar findings were observed in various patient groups, including dementia patients and cardiac arrest cases. This prompted CHOPR to support more BSN-prepared nurses and ongoing nursing workforce education. Our research also influenced the National Academy of Medicine’s 2010 suggestion of achieving an 80% nurse bachelor’s degree rate by 2020.
Health Disparities

CHOPR pioneered showing the link between hospital nursing care quality and racial/ethnic disparities in patient outcomes. Our research highlights that insufficient nurse staffing and resources lead to heightened mortality, readmissions, and lower patient satisfaction, particularly impacting minoritized patients.

International Reach
While our primary focus is on U.S. healthcare facilities, we’ve extended our efforts globally. Collaborating with colleagues in Chile, Australia, and Europe, we’ve pioneered similar work to enhance international work environments and nurse staffing standards.

Nurses4All Investigators

Linda H. Aiken, PhD, RN, FAAN
Nurses4All Principal Investigator

Linda Aiken’s pioneering research has created an evidence base showing the importance of nurses caring for fewer patients each, having most nurses with bachelor’s or higher qualifications, and improving nurse work environments.

Matthew D. McHugh PhD, JD, MPH, RN, FAAN
Nurses4All Principal Investigator

As principal investigator on multiple large-scale studies funded by NIH, AHRQ, and the Robert Wood Johnson Foundation, Dr. McHugh’s work has advanced the field of nursing outcomes and policy research by showing the value of investing in nursing as a vehicle to achieve a higher functioning health care system.

Eileen T. Lake, PhD, RN, FAAN
Nurses4All Co-Investigator

Dr. Lake developed the Practice Environment Scale of the Nursing Work Index, a foundational measure of nursing care performance to demonstrate nursing’s impact on patient outcomes. Dr. Lake’s goal with the index, which is used in over 23 languages, is to motivate managers and policymakers to make nursing resources a priority investment.

Dr. J. Margo Brooks Carthon

Margo Brooks Carthon, PhD, RN, FAAN
Nurses4All Co-Investigator

Dr. Margo Brooks Carthon is a health equity expert and was one of the first researchers to demonstrate empirical relationships between the quality of nursing care and racial inequities in outcomes. Through research, Dr. Brooks Carthon aims to determine the nursing care needs of adults with complex medical and social needs and collaborate with health system partners to develop innovative solutions to reduce health disparities.

Karen Lasater, PhD, RN, Postdoctoral Fellow

Karen B. Lasater, PhD, RN, FAAN
Nurses4All Co-Investigator

Dr. Lasater’s nursing research shows that better nurse resources lead to improved patient outcomes, without increasing costs. This generates new evidence on the economic impacts of staffing decisions.