Co-Occurrence of Respiratory Distress Syndrome-Associated Neonatal Mortality and Preterm Live Births: A Spatial Cluster Analysis

Abstract

Background: Respiratory distress syndrome (RDS) deaths and prematurity are impacted by geographically associated antenatal and perinatal factors. This study evaluated the spatial pattern of RDS-associated neonatal mortality and the preterm live birth rates and their co-occurrences. Methods: Population-based historical cohort study of all live births from mothers living in Sao Paulo State, Brazil, during 2004-2013. Exclusion criteria: <22 weeks gestational age, <400g birthweight or congenital anomalies. RDS-associated neonatal mortality was defined as deaths <28 days with ICD-10 codes P22.0 or P28 . 0. RDS-associated neonatal mortality and preterm live birth rates were aggregated per municipality and submitted to spatial first-order (crude rates and spatial moving average) and second-order (Global Moran Indicator - I - and Local Indicator of Spatial Autocorrelation - LISA) analysis, before and after applying a smoothing method for outliers with local Bayes equation. Spearman correlation test was applied to municipalities with significant LISA for both rates. Findings: 524094 preterm live births and 9464 RDS-associated neonatal deaths were included. Global Moran Indicator suggested non-random spatial distribution of preterm live births rates before (I=0·45; p=0·001) and after Bayesian smoothing (I=0·79; p=0·001). The same was observed for RDS-associated neonatal mortality rates before (I=0·26; p=0·007) and after smoothing (I=0·71; p=0·001). LISA maps showed similar clusters for both rates, however with a negative correlation (r=-0·22; p=0·009). Interpretations: Similar spatial clusters for RDS-associated neonatal mortality and live birth rates with negative correlation suggests an unequal neonatal specialized health structure availability throughout the State, indicating areas for improvement in perinatal care. Funding Statement: We thank FAPESP for the funding. Declaration of Interests: Dr. Scavacini Marinonio reports grants from Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), during the conduct of the study. Dr. Testoni Costa-Nobre reports grants from Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), during the conduct of the study. Dr. Harumi Miyoshi reports grants from Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), during the conduct of the study. Dr. Xavier Balda reports grants from Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), during the conduct of the study. Dr. Nema Areco reports grants from Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), during the conduct of the study. Ethics Approval Statement: The study was approved by the Ethics Committee of Universidade Federal de Sao Paulo, under the number 4.055.489, with informed consent waive, since it was a populational retrospective unidentified database.