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Archives of Disease in Childhood. Fetal and Neonatal Edition logoLink to Archives of Disease in Childhood. Fetal and Neonatal Edition
. 2003 Mar;88(2):F94–F97. doi: 10.1136/fn.88.2.F94

Infant to staff ratios and risk of mortality in very low birthweight infants

L Callaghan, D Cartwright, P O'Rourke, M Davies
PMCID: PMC1721503  PMID: 12598494

Abstract

Objectives: To assess the effect that infant to staff ratios, in the first three days of life, have on the survival to hospital discharge of very low birthweight infants (<1500 g), having adjusted for initial risk and unit workload.

Design: In a retrospective analysis of a cohort of patients, the number of infants per nurse per shift were averaged for the first three days after admission and related to risk of mortality by logistic regression analysis. Infant to staff ratio was divided into terciles of low (1.16–1.58), medium (1.59–1.70), and high (1.71–1.97) infants per staff member.

Subjects: 692 very low birthweight infants admitted to the Intensive Care Nursery, Royal Women's Hospital, Brisbane over a four year period from January 1996 to December 1999.

Main outcome measures: Survival to hospital discharge, adjusted for initial risk using the Clinical Risk Index for Babies (CRIB) score, and adjusted for unit workload using dependency scores.

Results: There were 80 deaths among the 692 babies analysed for the study period. The odds of mortality, adjusted for initial risk and infant dependency scores (unit workload), were improved by 82% when an infant/staff ratio of greater than 1.71 occurred, suggesting improved survival with the highest infant/staff ratio. The low and medium staffing levels corresponded with similar odds ratios for mortality.

Conclusions: Infants exposed to higher infant to staff ratios have an improved adjusted risk of survival to hospital discharge.

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Selected References

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  1. Baumer J. H., Wright D., Mill T. Illness severity measured by CRIB score: a product of changes in perinatal care? Arch Dis Child Fetal Neonatal Ed. 1997 Nov;77(3):F211–F215. doi: 10.1136/fn.77.3.f211. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Byrick R. J., Caskennette G. M. Audit of critical care: aims, uses, costs and limitations of a Canadian system. Can J Anaesth. 1992 Mar;39(3):260–269. doi: 10.1007/BF03008787. [DOI] [PubMed] [Google Scholar]
  3. Czaplinski C., Diers D. The effect of staff nursing on length of stay and mortality. Med Care. 1998 Dec;36(12):1626–1638. doi: 10.1097/00005650-199812000-00002. [DOI] [PubMed] [Google Scholar]
  4. Donchin Y., Gopher D., Olin M., Badihi Y., Biesky M., Sprung C. L., Pizov R., Cotev S. A look into the nature and causes of human errors in the intensive care unit. Crit Care Med. 1995 Feb;23(2):294–300. doi: 10.1097/00003246-199502000-00015. [DOI] [PubMed] [Google Scholar]
  5. Flood S. D., Diers D. Nurse staffing, patient outcome and cost. Nurs Manage. 1988 May;19(5):34-5, 38-9, 42-3. [PubMed] [Google Scholar]
  6. Fowlie P. W., Gould C. R., Parry G. J., Phillips G., Tarnow-Mordi W. O. CRIB (clinical risk index for babies) in relation to nosocomial bacteraemia in very low birthweight or preterm infants. Arch Dis Child Fetal Neonatal Ed. 1996 Jul;75(1):F49–F52. doi: 10.1136/fn.75.1.f49. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Giraud T., Dhainaut J. F., Vaxelaire J. F., Joseph T., Journois D., Bleichner G., Sollet J. P., Chevret S., Monsallier J. F. Iatrogenic complications in adult intensive care units: a prospective two-center study. Crit Care Med. 1993 Jan;21(1):40–51. doi: 10.1097/00003246-199301000-00011. [DOI] [PubMed] [Google Scholar]
  8. Keene A. R., Cullen D. J. Therapeutic Intervention Scoring System: update 1983. Crit Care Med. 1983 Jan;11(1):1–3. doi: 10.1097/00003246-198301000-00001. [DOI] [PubMed] [Google Scholar]
  9. Paneth N., Kiely J. L., Wallenstein S., Susser M. The choice of place of delivery. Effect of hospital level on mortality in all singleton births in New York City. Am J Dis Child. 1987 Jan;141(1):60–64. doi: 10.1001/archpedi.1987.04460010060024. [DOI] [PubMed] [Google Scholar]
  10. Phibbs C. S., Bronstein J. M., Buxton E., Phibbs R. H. The effects of patient volume and level of care at the hospital of birth on neonatal mortality. JAMA. 1996 Oct 2;276(13):1054–1059. [PubMed] [Google Scholar]
  11. Rautonen J., Mäkelä A., Boyd H., Apajasalo M., Pohjavuori M. CRIB and SNAP: assessing the risk of death for preterm neonates. Lancet. 1994 May 21;343(8908):1272–1273. doi: 10.1016/s0140-6736(94)92158-x. [DOI] [PubMed] [Google Scholar]
  12. Shamian J., Hagen B., Hu T. W., Fogarty T. E. The relationship between length of stay and required nursing care hours. J Nurs Adm. 1994 Jul-Aug;24(7-8):52–58. [PubMed] [Google Scholar]
  13. Tarnow-Mordi W. O., Hau C., Warden A., Shearer A. J. Hospital mortality in relation to staff workload: a 4-year study in an adult intensive-care unit. Lancet. 2000 Jul 15;356(9225):185–189. doi: 10.1016/s0140-6736(00)02478-8. [DOI] [PubMed] [Google Scholar]

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