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Optimising neonatal service provision for preterm babies born between 27 and 31 weeks gestation in England using national data, qualitative research and economic analysis

Principal investigator
Thillagavathie Pillay (Royal Wolverhampton NHS Trust)
Oliver Rivero-Arias (NPEU)
Care of the preterm or low birthweight infant, Organisation and delivery of maternity and neonatal care, Preterm birth
National Institute for Health Research
Start year
End year
NPEU Contact
Oliver Rivero-Arias


Project title

OPTI-PREM: Optimising neonatal service provision for preterm babies born between 27 and 31 weeks of gestation in England using national data, qualitative research and economic analysis

Project summary

Specialised services for neonates in England are delivered by neonatal units, including Neonatal Intensive Care Units (NICUs), Local Neonatal Units (LNUs) and Special Care Baby Units (SCBUs). Recent evidence from the UK indicates that, for extremely preterm babies born at 23-26 weeks of gestation, management in a NICU confers significant benefit in terms of improved survival to discharge. However, for pre-term babies born between 27-31 weeks of gestation, there is no evidence to guide the location of care and their management is spread, often arbitrarily, between NICUs and LNUs.

The study aims to explore whether the type of unit (NICU vs. LNU) in which neonatal care is delivered influences outcomes for preterm babies born between 27-31 weeks of gestation. The study findings will feed into the development of national policy on the optimal place of care for such babies and guide the commissioning and delivery of future neonatal health services in England.

There are four work streams in this study:

  • Work Stream 1: Clinical outcomes study to compare gestation specific mortality and major morbidities in babies managed in NICUs vs. LNUs.
  • Work Stream 2: Study of clinical care packages to identify the key differences in care provided in different types of neonatal units, and whether these differences are associated with gestation-specific differences in outcomes
  • Work Stream 3: Health economic study to compare the costs and outcomes of NICU care vs. LNU care
  • Work Stream4: Ethnographic study to explore parent's and clinicians' perspectives regarding to place of care

Staff in the NPEU are currently working on Work Stream 3 and will conduct a cost-effectiveness analysis (CEA) based on National Neonatal Research Database (NNRD) to compare NICU care with LNU care for preterm babies between 27-31 weeks of gestation. With linkage of data from Hospital Episode Statistics (HES) and Office of National Statistics (ONS) to the NNRD, we will also extend the time horizon of the economic evaluation up to one year of age. Since the babies were not randomly allocated to the two types of units (NICU vs. LNU), it is important for the analysis to account for potential bias arising from the confounding factors and reverse causality. Matching and instrumental variables will be employed to adjust for the observed and unobserved confounders between babies who received care in NICU and LNU. The study findings will provide important insights to address selection bias in CEA using observation data, which is a common methodological issue due to the non-random allocation of patients into the treatment and control groups.

NPEU Contacts

Oliver Rivero-Arias (

Miaoqing Yang (

Chief Investigator:

Thillagavathie Pillay (

OPTI-PREM webpage: