河野 由美

UNLABELLED: The objective of this study is to retrospectively evaluate the associations between socioeconomic status (SES), including nurturing environment, and developmental quotients (DQ) at age 3 in children born very preterm with birth weight ≤ 1500 g. This secondary analysis used follow-up data from the Improvement of NICU Practices and Team Approach Cluster Randomized Controlled Trial. Participants born < 32 weeks' gestation without major sensorimotor impairments were stratified into three groups: 22-24, 25-27, and 28-31 weeks. Multiple linear regression evaluated the associations between prenatal SES and DQ scores of the Kyoto Scale of Psychological Development (KSPD), adjusted for sex, parity, gestational age, small for gestational age, multiple births, and facilities. Post-discharge SES variables were subsequently added to assess associations with nurturing environment. Of 2148 eligible survivors, 1978 underwent KSPD testing and 1846 caregivers completed SES questionnaires. Higher parental education was positively associated with total DQ across all groups: 22-24 weeks (β = 2.246, 95% CI 0.015-4.477), 25-27 weeks (β = 1.589, 95% CI 0.408-2.770), and 28-31 weeks (β = 1.299, 95% CI 0.315-2.282). Group childcare utilization was associated with higher total DQ: 22-24 weeks (β = 3.397, 95% CI 0.893-5.901), 25-27 weeks (β = 1.851, 95% CI 0.591-3.111), and 28-31 weeks (β = 2.617, 95% CI 1.613-3.620). These associations remained after adjustments for postnatal morbidities. CONCLUSION: Among children born very preterm without major sensorimotor impairments, parental education and group childcare utilization were independently associated with more favorable cognitive outcomes at age 3. These results suggest the importance of socioeconomic and environmental support in optimizing developmental outcomes for this vulnerable population. WHAT IS KNOWN: • Prenatal and postnatal SES are associated with developmental outcomes in both preterm and term children. In addition, daily group childcare environments influence child development in the general population. WHAT IS NEW: • Among very preterm children without major sensorimotor impairments, including those born at 22-24 weeks' gestation, parental education and group childcare utilization are independently associated with more favorable cognitive and language outcomes at age 3.

BACKGROUND: The Improvement of Neonatal Intensive Care Unit (NICU) Practices and Team Approach Cluster-randomized Controlled Trial (INTACT) tested a multidisciplinary quality improvement (QI) program but did not show improved survival without neurodevelopmental impairment at 3 years among infants with very low birthweight. However, the program's potential effect on acute-phase outcomes in extremely preterm infants (< 28 weeks of gestation) warrants further evaluation. This secondary analysis aimed to assess the effect of the INTACT study's QI intervention based on participatory learning and action on acute morbidities during the NICU stay and outcomes at 3 years of age. METHODS: We performed a secondary analysis of data from the INTACT trial, a cluster-randomized controlled trial conducted in 40 Japanese NICUs from 2012-2014. Infants were stratified into two gestational age groups (22-24 weeks and 25-27 weeks). The primary outcome was a composite of seven acute morbidities (pulmonary air leak syndrome, pulmonary hemorrhage, sepsis, severe intraventricular hemorrhage, intestinal perforation, necrotizing enterocolitis, or circulatory collapse) between the intervention (QI program) and control groups. Secondary outcomes included chronic morbidities diagnosed before NICU discharge and long-term outcomes at 3 years of age. Multivariable logistic regression and Holm's correction for multiple comparisons were applied. RESULTS: In the 25-27-week subgroup, the intervention group showed a significantly lower rate of composite acute morbidity than the control group (31.3% vs. 40.3%; adjusted odds ratio [OR] 0.67; 95% confidence interval 0.50-0.90; p = 0.008). In the 22-24-week subgroup, composite acute morbidity did not differ significantly; however, sepsis (adjusted OR: 0.44, Holm-adjusted p = 0.010) and pulmonary hemorrhage (adjusted OR: 0.27, Holm-adjusted p = 0.028) were significantly reduced. After multivariable adjustment and Holm correction, no differences in neurodevelopmental outcomes at 3 years of age were observed between groups. CONCLUSIONS: This secondary analysis of a cluster-randomized controlled trial demonstrated that the intervention group receiving a NICU-specific QI program had reduced acute-phase morbidities, particularly among infants born between 22 and 27 weeks of gestation. Our findings highlight the potential for widespread clinical implementation of QI programs based on participatory learning and action in neonatal intensive care.