A study of 1.17 million hospital patients found that for-profit hospitals had about 11 more deaths per 1,000 medical admissions than nonprofits. 71% of their nurses said their workloads were unsafe.
Most people don’t choose their hospital. The ambulance goes to the nearest one, or the insurance plan decides. Few patients know whether that hospital is run as a nonprofit or by a company that answers to shareholders. Researchers at the University of Pennsylvania compared 143 for-profit and 798 nonprofit hospitals across 10 US states, using records from more than 1.17 million Medicare patients and surveys of 17,368 bedside nurses, to see whether ownership tracks with who survives a hospital stay. They also tested one specific explanation: how many patients each nurse is asked to care for.
How the study worked
The team, led by Matthew McHugh of Penn Nursing’s Center for Health Outcomes and Policy Research, looked at adult acute care hospitals, leaving out federal facilities such as VA hospitals. Patient outcomes came from Medicare records: whether patients died within 30 days of admission and whether they were readmitted within 30 days of going home. Patient ratings came from the national hospital survey that Medicare publishes.
Staffing came from the nurses themselves. The researchers surveyed registered nurses working at the bedside about their patient loads, their working conditions, burnout, and whether they would recommend their hospital. They then used a statistical method called mediation analysis to estimate how much of any gap between for-profit and nonprofit hospitals could be explained by differences in nurse staffing.
What for-profit hospitals looked like
Among patients admitted for medical conditions such as pneumonia or heart failure, 30-day mortality was 1.13 percentage points higher in for-profit hospitals. That works out to about 11 extra deaths for every 1,000 admissions. Among surgical patients, the gap was 0.48 percentage points, or about 5 extra deaths per 1,000.
Readmissions followed the same direction. For-profit hospitals readmitted about 20 more medical patients and 18 more surgical patients per 1,000 within a month of discharge. Patients also rated them lower: the share giving top marks was 4.45 percentage points smaller.
The nurses told a matching story. In for-profit hospitals, 71% said their assigned patient workloads were unsafe, compared with 54% in nonprofit hospitals. Burnout was 9 percentage points higher, and nurses at for-profit hospitals were far less likely to recommend their own hospital to family or friends, either as a place to be treated or a place to work.
How much nurse staffing explained
Staffing accounted for a large share of the gaps in for-profit hospitals’ results. It explained about 40% of the extra deaths among medical patients and 45% among surgical patients. For readmissions the share was smaller, 16% for medical and 30% for surgical patients. Staffing explained 31% of the gap in patient ratings and about two-thirds of the gap in nurse burnout.
That leaves a sizable part of the difference unexplained. Other factors that differ between hospitals, from equipment to physician staffing to which patients each hospital serves, could account for the rest.
“Treating safe nurse staffing as a core component of quality rather than a discretionary operating expense is especially important where incentives to cut labor costs are strongest,” McHugh said in a statement. The authors call for minimum nurse staffing requirements and more transparency about who owns hospitals.
What earlier studies found
The link between nurse staffing and survival is one of the most studied questions in hospital care. In 2002, a study of 168 Pennsylvania hospitals in JAMA, led by Linda Aiken, who is also an author of the new paper, found that each additional patient per nurse was associated with a 7% increase in the odds of a surgical patient dying within 30 days of admission. California remains the only US state with mandatory minimum nurse-to-patient ratios for hospitals.
The ownership question is less settled. Earlier research has generally found worse outcomes at for-profit hospitals, but studies using other methods have found smaller differences in mortality, or none at all. The new study’s contribution is to test a specific mechanism, staffing, in a large sample with nurse surveys attached.
What the study cannot show
This is an observational study, so it cannot prove that for-profit ownership or understaffing caused the extra deaths. For-profit and nonprofit hospitals may differ in location, size and patient mix in ways the analysis could not fully capture, even with risk adjustment. Mediation analysis also rests on assumptions about cause and effect that observational data cannot confirm.
The patient data cover Medicare fee-for-service admissions, so they mostly describe adults 65 and older, and the hospitals come from 10 states rather than the whole country. Staffing was measured through nurse surveys rather than payroll records. Averages also hide wide variation: some for-profit hospitals are well staffed and some nonprofits are not. Patients can look up a hospital’s ownership and its public ratings, but no single number tells them how a particular ward is staffed on a given night.
The study was funded by the National Institute of Nursing Research at the National Institutes of Health.
Source
McHugh MD, Lasater KB, Muir KJ, et al. “Patient Outcomes and Nurse Understaffing in For-Profit Hospitals.” Medical Care, 2026.
DOI: 10.1097/MLR.0000000000002376
Also cited
Aiken LH, Clarke SP, Sloane DM, Sochalski J, Silber JH. “Hospital nurse staffing and patient mortality, nurse burnout, and job dissatisfaction.” JAMA, 2002.
DOI: 10.1001/jama.288.16.1987
