The heterogeneous causal effects of neonatal care: a model of endogenous demand for multiple treatment options based on geographical access to care

• Published in: Health economics 2020-01, Vol.29 (1), p.46-60
• Main Authors: Mújica‐Mota, Rubén E., Landa, Paolo, Pitt, Martin, Allen, Mike, Spencer, Anne
• Format: Article
• Language: English
• Subjects: average treatment effects; Causality; Childbirth & labor; control function; Endogeneity; Endogenous; England; Female; geographical access; Health economics; Health Services Accessibility - statistics & numerical data; Hospital costs; Hospital Costs - statistics & numerical data; Hospitals; Humans; Infant; Infant mortality; Infant Mortality - trends; Infant, Newborn; Infants; instrumental variables; Intensive care; Intensive Care Units, Neonatal - statistics & numerical data; Length of stay; Length of Stay - statistics & numerical data; Medical prognosis; Models, Economic; multiple treatments; neonatal; Neonatal care; Neonatal units; Neonatology; policy evaluation; Pregnancy; Premature birth; Premature Birth - therapy; seemingly unrelated regression equations; latent factor; semi‐parametric; Tariffs
• ISSN: 1057-9230; 1099-1050
• DOI: 10.1002/hec.3970

Neonatal units in the UK are organised into three levels, from highest Neonatal Intensive Care Unit (NICU), to Local Neonatal Unit (LNU) to lowest Special Care Unit (SCU). We model the endogenous treatment selection of neonatal care unit of birth to estimate the average and marginal treatment effects of different neonatal designations on infant mortality, length of stay and hospital costs. We use prognostic factors, survival and hospital care use data on all preterm births in England for 2014–2015, supplemented by national reimbursement tariffs and instrumental variables of travel time from a geographic information system. The data were consistent with a model of demand for preterm birth care driven by physical access. In‐hospital mortality of infants born before 32 weeks was 8.5% overall, and 1.2 (95% CI: −0.7, 3.2) percentage points lower for live births in hospitals with NICU or SCU compared to those with an LNU according to instrumental variable estimates. We find imprecise differences in average total hospital costs by unit designation, with positive unobserved selection of those with higher unexplained absolute and incremental costs into NICU. Our results suggest a limited scope for improvement in infant mortality by increasing in‐utero transfers based on unit designation alone.