Association of nurse staffing and nursing workload with ventilator-associated pneumonia and mortality: a prospective, single-center cohort study.

BACKGROUND: Nurse understaffing and increased nursing workload have been associated with increased risk of adverse patient outcomes and even mortality.

AIM: To determine whether nurse staffing and nursing workload are associated with ventilator-associated pneumonia and mortality.

METHODS: This prospective, observational cohort study was conducted in a single tertiary-level teaching hospital in Finland during 2014-2015. The association between nurse staffing, nursing workload and prognosis was determined using daily nurse-to-patient ratios, Therapeutic Intervention Scoring System and Intensive Care Nursing Scoring System scores, and Intensive Care Nursing Scoring System indices. Ventilator-associated pneumonia was defined according to the Centers for Disease Control and Prevention criteria.

FINDINGS: Evaluable data was available for 85 patients. The overall ventilator-associated pneumonia and 28-day mortality rates were 23.5% and 35.3%, respectively. Nurse staffing, measured as the daily lowest nurse-to-patient ratio (P = 0.006) and median Intensive Care Nursing Scoring System index (P = 0.046), were significantly lower in patients with ventilator-associated pneumonia. In addition, nursing workload, measured as median scores obtained by the Therapeutic Intervention Scoring System (P = 0.009) and Intensive Care Nursing Scoring System (P = 0.03), was significantly higher in infected patients. The median (P = 0.02) and daily highest (P = 0.03) Intensive Care Nursing Scoring System scores were significantly higher in non-survivors.

CONCLUSIONS: Lower nurse staffing and increased nursing workload are associated with ventilator-associated pneumonia and mortality, demonstrating that adequate staffing is a prerequisite for the availability and quality of critical care services.