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Leadership History

Started in 1989 the founder, Dr. Linda H. Aiken, established The Center for Health Outcomes and Policy Research (CHOPR) to explore organizational effectiveness in health care with the potential to affect patient outcomes.

One of the first large studies the Center undertook, starting in 1991, was a national study of dedicated AIDS units to study the impact of hospital culture on nurses and patient care.

Aiken and her research team developed “a survey-based measure of the culture and context of care delivery” that was based on an earlier instrument called the Nursing Work Index (NWI). It was designed to measure nurses’ satisfaction with various aspects of their work. The team modified the NWI to create a new research instrument called the Revised Nursing Work Index (NWI-R), which would make it possible to empirically measure and describe the quality of the nursing work environment itself. Over time, subscales of the NWI-R were refined and five of the subscales became known as the Practice Environment Scale, which the National Quality Forum endorsed as a nurse-sensitive measure of hospital quality.

We were able to “create a unique database on all 210 hospitals in Pennsylvania without having to recruit any hospitals directly.” 

Thus, adding to the information nurses provided about these hospitals by linking their nurse survey data with patient discharge outcomes reported to a state agency. In the Center’s next big study, funded by the NIH Institute for Nursing Research and launched in 1996, 

“We used the same survey instrument but instead of recruiting hospitals, we surveyed 50 percent of all nurses licensed to practice in Pennsylvania and asked them to provide the names of their employing hospitals.” 

CHOPR Researchers have made rich use of this mother lode of data to pinpoint crucial interactions between nurses and their patients and other medical staff—from monitoring vital signs and managing pain to ensuring that precautions against infection are scrupulously followed. They have been able to map out the consequences of understaffing, budget cutting, extended shifts and nurse burnout.

Study after study, says Aiken, “shows that the greatest single major change a hospital could make [to ensure quality care] would be to improve the nursing environment.”

Note: The webmaster wishes to acknowledge the Robert Wood Johnson Foundation for sourcing the original CHOPR timeline in “Hospital Restructuring: Implications for Patient Outcomes and Workforce Policy”. 

Early study findings made possible by the Center’s work cross-referencing data from nurses with patient outcomes:

Nurse Burnout and Patient Satisfaction.” Medical Care, 42(2, supplement): 2004.

“Patients cared for on units that nurses characterized as having adequate staff, good administrative support, and good relations between doctors and nurses were more than twice as likely to report high satisfaction with their care, and their nurses reported significantly lower burnout.”

The Working Hours of Hospital Staff Nurses and Patient Safety.” Health Affairs, 23(4): 2004.

“The likelihood of making an error increased with longer work hours and was three times higher when nurses worked shifts lasting 12.5 hours or more.”


Educational Levels of Hospital Nurses and Surgical Patient Mortality,” Journal of the American Medical Association, 290(12): 2003.

“In hospitals with higher proportions of nurses educated at the baccalaureate level or higher, surgical patients experienced lower mortality and failure-to-rescue rates [death following the occurrence of an adverse event during hospitalization].” 

Effects of Hospital Care Environment on Patient Mortality and Nurse OutcomesJournal of Nursing Administration, 38(5): 2008.

“The odds of dying following common surgical procedures are reduced by 19 percent in environments that nurses rate better for nursing practic