Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Observational Study
. 2017 Jul 14;17(1):166.
doi: 10.1186/s12887-017-0921-x.

Comparing very low birth weight versus very low gestation cohort methods for outcome analysis of high risk preterm infants

Louise Im Koller-Smith  1 , Prakesh S Shah  2   3 , Xiang Y Ye  3 , Gunnar Sjörs  4 , Yueping A Wang  1 , Sharon S W Chow  1 , Brian A Darlow  5 , Shoo K Lee  2   3 , Stellan Håkanson  6 , Kei Lui  7   8 ; Australian and New Zealand Neonatal Network; Canadian Neonatal Network; Swedish Neonatal Quality Register
Collaborators, Affiliations
Observational Study

Comparing very low birth weight versus very low gestation cohort methods for outcome analysis of high risk preterm infants

Louise Im Koller-Smith et al. BMC Pediatr. .

Abstract

Background: Compared to very low gestational age (<32 weeks, VLGA) cohorts, very low birth weight (<1500 g; VLBW) cohorts are more prone to selection bias toward small-for-gestational age (SGA) infants, which may impact upon the validity of data for benchmarking purposes.

Method: Data from all VLGA or VLBW infants admitted in the 3 Networks between 2008 and 2011 were used. Two-thirds of each network cohort was randomly selected to develop prediction models for mortality and composite adverse outcome (CAO: mortality or cerebral injuries, chronic lung disease, severe retinopathy or necrotizing enterocolitis) and the remaining for internal validation. Areas under the ROC curves (AUC) of the models were compared.

Results: VLBW cohort (24,335 infants) had twice more SGA infants (20.4% vs. 9.3%) than the VLGA cohort (29,180 infants) and had a higher rate of CAO (36.5% vs. 32.6%). The two models had equal prediction power for mortality and CAO (AUC 0.83), and similarly for all other cross-cohort validations (AUC 0.81-0.85). Neither model performed well for the extremes of birth weight for gestation (<1500 g and ≥32 weeks, AUC 0.50-0.65; ≥1500 g and <32 weeks, AUC 0.60-0.62).

Conclusion: There was no difference in prediction power for adverse outcome between cohorting VLGA or VLBW despite substantial bias in SGA population. Either cohorting practises are suitable for international benchmarking.

Keywords: Benchmarking; Infant; Intensive care; Neonatal; Outcome; Premature; Small for gestational age; Very low birth weight.

PubMed Disclaimer

Conflict of interest statement

Authors information

List of site investigators and hospitals contributing data to the iNEO project.

Ethics approval and consent to participate

Study was approved by the South Eastern Sydney Local Health District Human Research Ethics Committee HREC reference number 13/041. Consent not applicable for de-identified data collection in aggregated report and analysis.

Consent for publication

Not applicable.

Competing interest

The authors have no competing interest to disclose. The authors have no financial relationships relevant to this article to disclose.

Publisher’s Note

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

Figures

Fig. 1
Fig. 1
Flow Chart of Study Cohort: derivation of the study infants from each neonatal network is summarised
See this image and copyright information in PMC

References

    1. Gilbert WM, Nesbitt TS, Danielsen B. The cost of prematurity: quantification by gestational age and birth weight. Obstet Gynecol. 2003;102(3):488–492. - PubMed
    1. Allen MC. Preterm outcomes research: a critical component of neonatal intensive care. Ment Retard Dev Disabil Res Rev. 2002;8(4):221–233. doi: 10.1002/mrdd.10044. - DOI - PubMed
    1. Mohangoo AD. Blondel Ba, Gissler M, Velebil P, Macfarlane a, Zeitlin J: international comparisons of fetal and neonatal mortality rates in high-income countries: should exclusion thresholds be based on birth weight or gestational age? PLoS One. 2013;8(5):e64869. doi: 10.1371/journal.pone.0064869. - DOI - PMC - PubMed
    1. Larroque B, Ancel PY, Marret S, Marchand L, Andre M, Arnaud C, Pierrat V, Roze JC, Messer J, Thiriez G, et al. Neurodevelopmental disabilities and special care of 5-year-old children born before 33 weeks of gestation (the EPIPAGE study): a longitudinal cohort study. Lancet. 2008;371(9615):813–820. doi: 10.1016/S0140-6736(08)60380-3. - DOI - PubMed
    1. Smith LK, Draper ES, Field D. Long-term outcome for the tiniest or most immature babies: survival rates. Semin Fetal Neonatal Med. 2014;19(2):72–77. doi: 10.1016/j.siny.2013.11.002. - DOI - PubMed

Publication types

MeSH terms