Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Neonatal intensive care unit occupancy rate and probability of discharge of very preterm infants



To assess the association of NICU occupancy with probability of discharge and length of stay (LOS) among infants born <33 weeks gestational age (GA).

Study design

Retrospective study of 3388 infants born 23–32 weeks GA, admitted to five Level 3/4 NICUs (2014-2018) and discharged alive. Standardized ratios of observed-to-expected number of discharges were calculated for each quintile of unit occupancy. Multivariable linear regression models were used to assess the association between occupancy and LOS.


At the lowest unit occupancy quintiles (Q1 and Q2), infants were 12% and 11% less likely to be discharged compared to the expected number. At the highest unit occupancy quintile (Q5), infants were 20% more likely to be discharged. Highest occupancy (Q5) was also associated with a 4.7-day (95% CI 1.7, 7.7) reduction in LOS compared Q1.


NICU occupancy was associated with likelihood of discharge and LOS among infants born <33 weeks GA.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Standardized ratios for probability of discharge according to NICU occupancy quintiles.
Fig. 2: Standardized ratios for probability of discharge by NICU occupancy quintile stratified according to discharge destination.

Similar content being viewed by others

Data availability

Data for this study cannot be shared publicly as it is bound by confidentiality agreements governed by hospital and government privacy offices. Aggregate data may be made available from the corresponding author [MB] on reasonable request.


  1. Beltempo M, et al. on behalf of the Canadian Neonatal Network Annual Report Committee. Canadian Neonatal Network 2020 Annual report. Toronto, Ontario; 2021.

  2. Lee SK, Beltempo M, McMillan DD, Seshia M, Singhal N, Dow K, et al. Outcomes and care practices for preterm infants born at less than 33 weeks’ gestation: a quality-improvement study. CMAJ. 2020;192:E81–E91.

    Article  PubMed  PubMed Central  Google Scholar 

  3. Lee HC, Bennett MV, Schulman J, Gould JB, Profit J. Estimating length of stay by patient type in the neonatal intensive care unit. Am J Perinatol. 2016;33:751–7.

    Article  PubMed  Google Scholar 

  4. Seaton SE, Barker L, Draper ES, Abrams KR, Modi N, Manktelow BN. Estimating neonatal length of stay for babies born very preterm. Arch Dis Child Fetal Neonatal Ed. 2019;104:F182–f186.

    Article  PubMed  Google Scholar 

  5. Seaton SE, Draper ES, Adams M, Kusuda S, Håkansson S, Helenius K, et al. Variations in neonatal length of stay of babies born extremely preterm: an international comparison between iNeo networks. J Pediatr. 2021;233:26–32.e26.

    Article  PubMed  Google Scholar 

  6. Seaton SE, Barker L, Jenkins D, Draper ES, Abrams KR, Manktelow BN. What factors predict length of stay in a neonatal unit: a systematic review. BMJ Open. 2016;6:e010466.

    Article  PubMed  PubMed Central  Google Scholar 

  7. Melnyk BM, Feinstein NF, Alpert-Gillis L, Fairbanks E, Crean HF, Sinkin RA, et al. Reducing premature infants’ length of stay and improving parents’ mental health outcomes with the Creating Opportunities for Parent Empowerment (COPE) neonatal intensive care unit program: a randomized, controlled trial. Pediatrics. 2006;118:e1414–1427.

    Article  PubMed  Google Scholar 

  8. Profit J, McCormick MC, Escobar GJ, Richardson DK, Zheng Z, Coleman-Phox K, et al. Neonatal intensive care unit census influences discharge of moderately preterm infants. Pediatrics. 2007;119:314–9.

    Article  PubMed  Google Scholar 

  9. COMMITTEE ON FETUS AND NEWBORN, Barfield WD, Papile L-A, Baley JF, Benitz W, Cummings J. et al. Levels of neonatal care. Pediatrics. 2012;130:587–97.

    Article  Google Scholar 

  10. Rizzolo A, Shah PS, Bertelle V, Makary H, Ye XY, Abenhaim HA, et al. Association of timing of birth with mortality among preterm infants born in Canada. J Perinatol. 2021;41:2597–606.

    Article  PubMed  Google Scholar 

  11. Beltempo M. Rapport sur l’évaluation des besoins régionaux en néonatologie au Québec. Rapport produit pour le Ministère de la santé et des Services sociaux du Québec. Montréal, QC, Canada; 2021.

  12. Canadian Neonatal Network. Abstarctor’s Manual v2.1.2. 2014.

  13. Shah PS, Seidlitz W, Chan P, Yeh S, Musrap N, Lee SK, et al. Internal audit of the Canadian neonatal network data collection system. Am J Perinatol. 2017;34:1241–9.

    Article  PubMed  Google Scholar 

  14. Kramer MS, Platt RW, Wen SW, Joseph KS, Allen A, Abrahamowicz M, et al. A new and improved population-based Canadian reference for birth weight for gestational age. Pediatrics. 2001;108:E35.

    Article  CAS  PubMed  Google Scholar 

  15. Beltempo M, Shah PS, Ye XY, Afifi J, Lee S, McMillan DD, et al. SNAP-II for prediction of mortality and morbidity in extremely preterm infants. J Matern Fetal Neonatal Med. 2019;32:2694–701.

  16. Ahmed N, Devitt KS, Keshet I, Spicer J, Imrie K, Feldman L, et al. A systematic review of the effects of resident duty hour restrictions in surgery: impact on resident wellness, training, and patient outcomes. Ann Surg. 2014;259:1041–53.

    Article  PubMed  Google Scholar 

  17. McHugh MD, Aiken LH, Sloane DM, Windsor C, Douglas C, Yates P. Effects of nurse-to-patient ratio legislation on nurse staffing and patient mortality, readmissions, and length of stay: a prospective study in a panel of hospitals. Lancet. 2021;397:1905–13.

    Article  PubMed  PubMed Central  Google Scholar 

  18. Cho E, Park J, Choi M, Lee HS, Kim EY. Associations of nurse staffing and education with the length of stay of surgical patients. J Nurs Scholarsh. 2018;50:210–8.

    Article  PubMed  Google Scholar 

  19. Lemieux-Bourque C, Piedboeuf B, Gignac S, Taylor-Ducharme S, Julien AS, Beltempo M. Comparison of three nursing workload assessment tools in the neonatal intensive care unit and their association with outcomes of very preterm infants. Am J Perinatol. 2022;39:640–5.

  20. Lee HC, Bennett MV, Schulman J, Gould JB. Accounting for variation in length of NICU stay for extremely low birth weight infants. J Perinatol. 2013;33:872–6.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Puthattayil ZB, Luu TM, Beltempo M, Cross S, Pillay T, Ballantyne M, et al. Risk factors for re-hospitalization following neonatal discharge of extremely preterm infants in Canada. Paediatr Child Health. 2021;26:e96–e104.

    Article  PubMed  Google Scholar 

  22. Mosquera RA, Avritscher EB, Samuels CL, Harris TS, Pedroza C, Evans P, et al. Effect of an enhanced medical home on serious illness and cost of care among high-risk children with chronic illness: a randomized clinical trial. JAMA. 2014;312:2640–8.

    Article  CAS  PubMed  Google Scholar 

  23. Shah PS, Mirea L, Ng E, Solimano A, Lee SK. Canadian Neonatal N. Association of unit size, resource utilization and occupancy with outcomes of preterm infants. J Perinatol. 2015;35:522–9.

    Article  CAS  PubMed  Google Scholar 

  24. Beltempo M, Lacroix G, Cabot M, Blais R, Piedboeuf B. Association of nursing overtime, nurse staffing and unit occupancy with medical incidents and outcomes of very preterm infants. J Perinatol. 2018;38:175–80.

    Article  CAS  PubMed  Google Scholar 

  25. Sherenian M, Profit J, Schmidt B, Suh S, Xiao R, Zupancic JA, et al. Nurse-to-patient ratios and neonatal outcomes: a brief systematic review. Neonatology. 2013;104:179–83.

    Article  PubMed  Google Scholar 

  26. Rogowski JA, Staiger D, Patrick T, Horbar J, Kenny M, Lake ET. Nurse staffing and NICU infection rates. JAMA Pediatr. 2013;167:444–50.

    Article  PubMed  PubMed Central  Google Scholar 

  27. Blayney MC, Donaldson L, Smith P, Wallis C, Cole S, Lone NI. Intensive care unit occupancy and premature discharge rates: a cohort study assessing the reporting of quality indicators. J Crit Care. 2020;55:100–7.

    Article  CAS  PubMed  Google Scholar 

  28. Fergusson NA, Ahkioon S, Ayas N, Dhingra VK, Chittock DR, Sekhon MS, et al. Association between intensive care unit occupancy at discharge, afterhours discharges, and clinical outcomes: a historical cohort study. Can J Anaesth. 2020;67:1359–70.

    Article  PubMed  Google Scholar 

  29. Vollam S, Dutton S, Lamb S, Petrinic T, Young JD, Watkinson P. Out-of-hours discharge from intensive care, in-hospital mortality and intensive care readmission rates: a systematic review and meta-analysis. Intensive Care Med. 2018;44:1115–29.

    Article  PubMed  PubMed Central  Google Scholar 

Download references


The authors gratefully acknowledge all site investigators and abstractors of the Canadian Neonatal Network. We also thank the staff at the Maternal-Infant Care (MiCare) Research Centre at Mount Sinai Hospital, Toronto, ON for organizational support of the Canadian Neonatal Network.


MB holds an Early Career Investigator Grant from the CIHR Institute of Human Development, Child and Youth Health (IHDCYH), a Research Grant Funding from the FRSQ Clinical Research Scholar Career Award Junior 1, and an Early Career Investigator Grant from the Montreal Children’s Hospital Foundation.

Author information

Authors and Affiliations




MB conceptualized and designed the study, drafted the manuscript, and adjusted the manuscript according to the comments of co-authors. SP collected and analyzed the data, contributed to study design and critically reviewed the manuscript. AL, SM, VB and BP provided administrative support for data access. ES, GL, AL, STD, SM, VB and BP provided review and critical appraisal of the manuscript.

Corresponding author

Correspondence to Marc Beltempo.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Beltempo, M., Sargi, E., Patel, S. et al. Neonatal intensive care unit occupancy rate and probability of discharge of very preterm infants. J Perinatol 43, 490–495 (2023).

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


Quick links