Using the median cutoffs for hospital-level scores shown in , of the 168 hospitals, 43 (26%) were in the poor environment category, 83 (49%) were in the mixed category, and 42 were in the better category. In terms of structure, 19% were large (more than 500 beds), 36% were teaching hospitals, and 28% were high-technology hospitals offering open-heart surgery, major organ transplants, or both. The average hospital-level staffing was 5.7 patients per nurse, although staffing was lower in hospitals with poor care environments (6.0) than in hospitals with mixed and better environments (5.8 and 5.3, respectively—poor and mixed environments were significantly different from best, P = .02 and P = .03, respectively, by Scheffé post hoc tests). The mean proportion of nurses with bachelor of science in nursing (BSN) degrees was 31% overall and was lower in the hospitals with poor and mixed care environments (29% and 30%, respectively) than in hospitals with better environments (35%); however, these were only marginally significantly different (P < .10). Overall, 2% of the surgical patients died within 30 days of admission, as did 8% of those who developed complications (ie, 8% of the patients at risk experienced failure to rescue).
shows the distribution of nurse characteristics and nurse reports overall and across the 3 categories of hospitals by type of practice environment. Overall, 6% of the 10,184 nurses in our sample were men, the average age was 40 years, and the average number of years working as a nurse was approximately 14 years. Approximately 1 of 3 nurses (31%) worked on medical/surgical units, and 18% worked on intensive care units. Forty percent of the nurses had bachelor's degrees or higher, 35% held diplomas, and 25 had associate degrees as their highest credentials in nursing. Breaking down the nurses by type of hospitals, higher percentages of the nurses in hospitals with poor care environments reported high burnout levels and dissatisfaction with their jobs. The percentage of nurses who reported that the quality of care was poor or fair (rather than good or excellent) was twice as high in hospitals with poor care environments as in hospitals with better ones. A similar pattern was observed with respect to the likelihood of nurses lacking confidence that patient care problems would be resolved by management and that their patients were able to manage their own care at discharge. Higher proportions of those in the hospitals with poor and mixed environments were unwilling to recommend their hospital to a family member.
Nurse Characteristics, Outcomes, Reports of Adverse Events, and Assessments of Patient Care Quality in the Study Hospitals, by Care Environment Categories
shows the results of the modeling of the effects of better versus mixed or mixed versus poor care environments on nurse outcomes and nurse reports of quality of care, controlling for nurse characteristics and the clustering of patients within hospitals. The effects of care environments were first analyzed separately and then jointly. The care environment and nurse staffing had significant effects on burnout and job dissatisfaction, although only the care environment had a significant effect on intentions to leave. The coefficients in the right panel of imply that in fully adjusted models (where care environments and staffing are entered together), the odds of nurses being burned out, being dissatisfied with their jobs, and intending to leave were lower by 24% (ie, (1-0.76) × 100), 25%, and 13% in hospitals in the mixed category relative to the poor category and in the better category relative to the mixed one. The results of the logistic regression models used here allow us to determine the effect of moving from better to poor staffing by squaring the odds ratios. Therefore, nurses working in the hospitals with better care environments have odds on experiencing these deleterious outcomes, which were 24% (ie, (1-0.872) × 100) to 42% lower than the odds for nurses working in the hospitals with the poor environments. In addition, even after controlling for the effects of care environments, the odds of nurses reporting high burnout or dissatisfaction increased by roughly one-fifth and one-tenth, respectively, with each increase of 1 patient per nurse in mean workloads in their hospitals. Nurses in hospitals with better care environments were also much less likely to provide negative assessments of the care in their hospitals. The odds on nurses reporting concerns with patient care quality were between 42% and 69% lower in hospitals with better care environments than in hospitals with poor ones.
Adjusted Odds Ratios (Or) Indicating the Effect of Better Versus Mixed (or of Mixed vs Poor) Care Environment and Nurse Staffing on Nurse Outcomes
Finally, shows that care environments, nurse staffing, and nurse education were associated with 30-day mortality and failure to rescue, both individually and jointly, in models controlling for patient and hospital characteristics (in the case of the effect of the care environment on failure to rescue, the association was marginally significant, P = .06). In the final model, taking all patient and nursing factors into consideration, the likelihood of patients dying within 30 days of admission was 14% lower in hospitals with better care environments than in hospitals with poor care environments (ie, (1-0.932) × 100). The odds on patients dying in hospitals with better care environments were lower by 14% than in hospitals with poor ones. The odds on patients dying in hospitals with an average workload of 8 patients per nurse is 1.26 times greater than in hospitals with mean workloads of 4 patients per nurse. The odds ratio of 0.96 associated with nurse education indicates that each 10% increase in the proportion of nurses with BSN was associated with a 4% decrease in risk of death. By extension, the odds of patients dying in hospitals in which 60% of the nurses held BSN versus hospitals in which 20% (or 40% fewer) of the nurses were BSN prepared would be lower by 15% (ie, (1-0.964) × 100).
Adjusted Odds Ratios (Or) Indicating the Effect of Better Versus Mixed (or of Mixed vs Poor) Care Environment, Nurse Staffing, and Nurse Education on Mortality and Failure to Rescue
Direct standardization methods were used to express the effects of the care environment, nurses' education, and nurse staffing together in terms of extrapolated death and failure-to-rescue rates under various hypothetical conditions. The “average” hospital had a mixed care environment, a 6:1 ratio of patients to nurses, and a nursing staff that consisted of 30% BSN-prepared nurses. Overall, the 30-day mortality rate for general surgical patients was 19.5 per 1,000 admissions, and 84.4 per 1,000 surgical patients with complications died within 30 days of admission. Our models imply that if all hospitals had better care environments, a 4:1 patient-to-nurse ratio, and 60% BSN-prepared staff nurses, the overall mortality rate would have been 15.6 per 1,000 admissions, and the failure-to-rescue rate would be 68.2 per 1,000. Under the worst case scenario (a poor care environment, 8:1 patient-to-nurse ratio, and 20% BSN-prepared staff nurses), the mortality rate would have been 25.1 per 1,000 admissions, and the failure-to-rescue rate would be 105.9 per 1,000. All else being equal, hospitals that ranked poorly on all 3 factors had mortality rates and failure-to-rescue rates that were 61% and 55% higher, respectively, than hospitals that ranked high on all 3.