The effect of the nursing practice environment, nurse staffing and nursing care processes on in-patient mortality, hospital-acquired infections, pressure injuries and patient falls

Background: The relationship between structural elements of nursing, including the nursing practice environment and nurse staffing, and nursing-sensitive patient outcomes has been the subject of a substantial quantity of research. Efforts to enhance patient safety and evaluate the quality of healthcare have led to additional research that focuses on the relationship between the processes of nursing care and patient outcomes. Despite these research endeavours, studies simultaneously investigating the relationships between nursing structure variables, the processes of nursing care, and patient outcomes are limited. As a result, little is known about the relationships between the nursing practice environment, nurse staffing, nursing care processes, and nursing-sensitive patient outcomes.

Aim: To investigate the association between the nursing practice environment, nurse staffing, and the processes of nursing care on four nursing-sensitive patient outcomes including 30-day inpatient mortality, hospital-acquired infections, pressure injuries and patient falls.

Method: This multi-phase, multi-source, quantitative study was conducted at one large hospital in metropolitan Sydney, Australia. Phase A involved a cross-sectional survey administered to nurses. Data were collected on nurse demographics, nursing practice environment, staffing levels, work patterns, and missed nursing care using validated instruments. In phase B, retrospective data were collected on the processes of care related to the four outcomes of interest from administrative data sources. Process of care measures included data on the escalation of patient care following deterioration, hand hygiene compliance, pressure injury prevention practices and falls prevention practices. In phase C, patient outcome measures were collected and included risk-adjusted 30-day inpatient mortality, hospital-acquired infections, pressure injuries and patient falls. Data for Phase C were sourced from the admitted patient databases for the period July 2018 to June 2021. To link these data from phase A, B and C, the nursing survey and processes of nursing care data were aggregated at the ward level. Using the ward-level data, variables were then derived for each episode of care based on ward movements. To do this, we applied weights based on the amount of time each patient spent in each ward. Descriptive statistics were used to summarise patient, admission and ward characteristics. Pearson’s correlation coefficient was used to assess the correlation between the nursing structure variables and the process of nursing care variables. Multiple and mixed logistic regression models were used to analyse the association between the nursing practice environment, nurse staffing, processes of nursing care and nursing-sensitive patient outcomes.

Result: In Phase A of the study the nursing survey was completed by 361 nurses from 17 wards and included medical, surgical, intensive care and sub-acute units. In Phase B processes of nursing care were assessed, including 30,011 reported cases of patient deterioration, and 13,440 hand hygiene moments for the study period. Data on processes of nursing care related to pressure injury prevention were assessed from 633 patients and fall prevention practices for 601 patients who had experienced a fall were analysed. Data on pressure injury and fall prevention practices were only available for limited periods during the study. Phase C included data collection from 71,257 episodes of care for 40,455 patients in the three-year period. The episodes of care included 1617 episodes of 30-day inpatient mortality, 2,037 episodes with hospital-acquired infections, 312 episodes with hospital-acquired pressure injuries and 1,005 episodes of care with patient falls.

Evidence of associations between some nursing structure and process of care variables with 30-day inpatient mortality were identified. Multiple logistic regression analysis indicated that nurse staffing was associated with 30-day inpatient mortality, with each additional patient per nurse the odds of patient mortality increased by 24%. For each 10% increase in missed care related to patient surveillance, the odds of 30-day inpatient mortality increased by 16%. Escalation of care from a rapid response call to a cardiopulmonary resuscitation event was associated with 30-day inpatient mortality. For every 10% increase in cardiopulmonary resuscitation events, the odds of 30-day inpatient mortality decreased by 16%.

Evidence of associations between some nursing structure and process of care variables with hospital-acquired infections were identified. The odds of hospital-acquired infections decreased by 19% for every 10% increase in nurses' compliance with hand hygiene and decreased by 7% for each standard deviation increase in score on the nursing practice environment. An increase of one patient per nurse was associated with a 42% increased risk of hospital-acquired infections.

The relationships between structure, process and outcome measures for pressure injuries and patient falls was impacted by data availability for process of care measures and the relatively rare nature of these outcomes during the study period. The odds of all stages of pressure injuries were 25% higher with a one standard deviation increase in the nursing practice environment. There was no evidence of an association between the nursing practice environment and patient falls.

Conclusion: This study has provided new knowledge on the important relationship between the nursing practice environment, nurse staffing, and the processes of care on four nursing-sensitive patient outcomes in a hospital setting. Findings from this study have identified the importance of nurse staffing, a supportive nursing practice environment, timely escalation of care and strict hand hygiene compliance in ensuring patient safety and reducing the risk of hospital-acquired infections. Findings from this Doctoral study can be used by nurse leaders, healthcare institutions and policy makers to implement effective nursing care practices to enhance the overall safety and quality of patient care in acute care hospitals. This has the potential to contribute to improving patient outcomes and creating safer healthcare environments.