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

  • Miia M. Jansson
    Corresponding author. Address: Research Group of Surgery, Anesthesiology and Intensive Care, Medical Research Center Oulu, University of Oulu, P.O. Box 8000, FI-90014, Oulu, Finland. Tel.: +358 44 592 59 48.
    Research Group of Surgery, Anesthesiology and Intensive Care, Medical Research Center Oulu, Oulu, Finland
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  • Hannu P. Syrjälä
    Department of Infection Control, Oulu University Hospital, Oulu, Finland
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  • Tero I. Ala-Kokko
    Research Group of Surgery, Anesthesiology and Intensive Care, Medical Research Center Oulu, Oulu, Finland

    Division of Intensive Care, Department of Anesthesiology, Oulu University Hospital, Oulu, Finland
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Published:December 07, 2018DOI:



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


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


      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.


      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.


      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.


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