Reference
Aiken, L. H., Simonetti, M., Sloane, D. M., Cerón, C., Soto, P., Bravo, D., Galiano, A., Behrman, J. R., Smith, H. L., McHugh, M. D., & Lake, E. T. (2021). Hospital nurse staffing and patient outcomes in Chile: a multilevel cross-sectional study. The Lancet. Global health, 9(8), e1145–e1153. https://doi.org/10.1016/S2214-109X(21)00209-6
At a glance
This multilevel cross-sectional study of 40 hospitals in Chile found that hospital nurse staffing levels positively correlated with more favorable patient health outcomes and better satisfaction with care received. Lower patient mortality, fewer 30-day readmissions, and a shorter length of stay were all observed.
What is already known
For a number of years, staffing levels in hospital settings have been shown to be associated with better patient outcomes, particularly in reducing 30-day mortality. Many previous studies — mostly retrospective observational studies with cross-sectional data — examined nursing factors that explained the association but not the causality.
This study investigated the association between hospital nurse staffing and both patient outcomes and hospital productivity. It is the largest study conducted in Latin America on this topic.
Design and method
This was a multilevel cross-sectional study conducted in Chile. Its aim was to estimate the associations between nursing staff and work-environment quality with respect to 30-day inpatient mortality, 30-day readmission, length of stay, patient experience, and quality of care.
Interviews were conducted with nurses working in public and private hospitals for high-complexity adults. The interviews were then correlated with patient satisfaction data and diagnosis-related group (DRG) discharge data.
For each hospital, at least 50 satisfaction responses were collected from patients admitted to medical and surgical units for a period of at least 48 hours and able to supply this information.
Multilevel random-effects logistic regression models and zero-truncated negative binomial regression models were applied for statistical analyses, grouping patients within hospitals.
Main findings
1,652 nurses from 40 different hospitals (34 public and 6 private) participated in the interviews. Satisfaction data from 2,013 patients and discharge data from 761,948 hospitalized patients were collected.
Adjustment was made based on patient characteristics, and it was observed that nurse staffing was related to patient outcomes. The results also showed that the work environment correlated with patient satisfaction and nurse quality ratings. For each patient added to the nurses’ workload, an increase in mortality, readmission, and length of stay was observed.
New findings
The study found that Chilean hospitals on average have fewer nurses than the international standard. The average for hospital nurses is 14.1 patients each, with a large difference between private and public hospitals (8.7 vs. 14.7, respectively). In public hospitals, one nurse follows between 9 to 24 patients. For each additional patient, the risk of death increases by 4%. In hospitals that had 18 patients per nurse, when compared with hospitals with 8 patients per nurse, the risk of death increased by 41%, the probability of readmission at 30 days increased by 20%, and the length of stay increased by 41%. Furthermore, the likelihood of rating the hospital positively decreased by 68%, and the willingness to recommend that hospital to others decreased by 55%.
Limitations of the study
The study design did not allow a causal relationship to be established between nurses and patient outcomes. However, the results of the study are similar to other studies that were cross sectional and had performed longitudinal analyses. Some of the measures used (e.g., quality and safety), although validated, partly lend themselves to subjective interpretation.
Areas for future work
From the analysis of the demographic profile of Chilean nurses, it was observed that their careers are shorter than those of their US colleagues, which might suggest the need for improvement of their working conditions.
Increasing staffing levels by implementing public policies as implemented in other countries, where the maximum limit of patients per single nurse is 10, would be an investment largely repaid by the number of hospitalization days saved. This savings in inpatient days would also create a greater turnover of patients, allowing for shorter waiting lists for surgery.
Making changes in the hospital working environment would improve the quality of care and patient satisfaction while optimizing the production efficiency of the hospital system.
Edited by Daiana Campani
