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Association of nurse staffing and unit occupancy with mortality and morbidity among very preterm infants: a multicentre study
  1. Marc Beltempo1,2,
  2. Sharina Patel1,
  3. Robert W Platt1,2,
  4. Anne-Sophie Julien3,
  5. Régis Blais4,
  6. Valerie Bertelle5,
  7. Anie Lapointe6,
  8. Guy Lacroix7,
  9. Sophie Gravel8,
  10. Michèle Cabot9,
  11. Bruno Piedboeuf10
  12. on behalf of the Quebec investigators of the Canadian Neonatal Network
    1. 1 Department of Pediatrics, McGill University, Montreal, Quebec, Canada
    2. 2 Departments of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Quebec, Canada
    3. 3 Département de mathématiques et de statistique, Université Laval, Quebec City, Quebec, Canada
    4. 4 Département de gestion, d’évaluation et de politique de santé, Université de Montréal, Montreal, Quebec, Canada
    5. 5 Departement of Pediatrics, Université de Sherbooke, Sherbrooke, Quebec, Canada
    6. 6 Departement of Pediatrics, Université de Montréal, Montreal, Quebec, Canada
    7. 7 Department of Economics, Université Laval, Quebec City, Quebec, Canada
    8. 8 Division of Neonatalogy, CHU Sainte-Justine, Montreal, Quebec, Canada
    9. 9 Division of Neonatalogy, CHU de Québec-Université Laval, Quebec City, Quebec, Canada
    10. 10 Departement of Pediatrics, Université Laval, Quebec City, Quebec, Canada
    1. Correspondence to Dr Marc Beltempo, Pediatrics, Montreal Children's Hospital - McGill University Health Centre, Montreal, Canada; marc.beltempo{at}


    Objective In a healthcare system with finite resources, hospital organisational factors may contribute to patient outcomes. We aimed to assess the association of nurse staffing and neonatal intensive care unit (NICU) occupancy with outcomes of preterm infants born <33 weeks’ gestation.

    Design Retrospective cohort study.

    Setting Four level III NICUs.

    Patients Infants born 23–32 weeks’ gestation 2015–2018.

    Main outcome measures Nursing provision ratios (nursing hours worked/recommended nursing hours based on patient acuity categories) and unit occupancy rates were averaged for the first shift, 24 hours and 7 days of admission of each infant. Primary outcome was mortality/morbidity (bronchopulmonary dysplasia, severe neurological injury, retinopathy of prematurity, necrotising enterocolitis and nosocomial infection). ORs for association of exposure with outcomes were estimated using generalised linear mixed models adjusted for confounders.

    Results Among 1870 included infants, 823 (44%) had mortality/morbidity. Median nursing provision ratio was 1.03 (IQR 0.89–1.22) and median unit occupancy was 89% (IQR 82–94). In the first 24 hours of admission, higher nursing provision ratio was associated with lower odds of mortality/morbidity (OR 0.93, 95% CI 0.89 to 0.98), and higher unit occupancy was associated with higher odds of mortality/morbidity (OR 1.19, 95% CI 1.04 to 1.36). In causal mediation analysis, nursing provision ratios mediated 47% of the association between occupancy and outcomes.

    Conclusions NICU occupancy is associated with mortality/morbidity among very preterm infants and may reflect lack of adequate resources in periods of high activity. Interventions aimed at reducing occupancy and maintaining adequate resources need to be considered as strategies to improve patient outcomes.

    • Neonatology
    • Health Care Economics and Organizations
    • Intensive Care Units, Neonatal

    Data availability statement

    No data are available.

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    • Collaborators The Quebec investigators of the Canadian Neonatal Network include Marc Beltempo, MD, (Associate Director, Canadian Neonatal Network and Site Investigator), Montreal Children’s Hospital at McGill University Health Centre, Montréal, Québec; Victoria Bizgu, MD, Jewish General Hospital, Montréal, Québec; Keith Barrington, MBChB, Anie Lapointe, MD and Guillaume Ethier, NNP, Hôpital Sainte-Justine, Montréal, Québec; Christine Drolet, MD and Bruno Piedboeuf, MD, Centre Hospitalier Universitaire de Québec, Sainte Foy, Québec; Martine Claveau, MSc, LLM, NNP, Montreal Children’s Hospital at McGill University Health Centre, Montréal, Québec; Marie St-Hilaire, MD, Hôpital Maisonneuve-Rosemont, Montréal, Québec; Valerie Bertelle, MD and Edith Masse, MD, Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, Québec.

    • Contributors MB had full access to all the data in the study and takes responsibility for the integrity of the data for the accuracy of the data analysis and for the overall content as the guarantor. All authors contributed to the study concept and design. Data acquisition and analysis: SP and ASJ with oversight by MB and GL. Interpretation of data: all authors. Drafting of the manuscript: MB and SP.

    • Funding This project was funded by an Early Career Investigator Grant from the Montreal Children's Hospital Foundation

    • Disclaimer The funding agencies had no role in the design or conduct of the study; the collection, management, analysis or interpretation of the data; the preparation, review or approval of the manuscript; or the decision to submit the manuscript for publication.

    • Competing interests None declared.

    • Provenance and peer review Not commissioned; externally peer reviewed.

    • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.

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