Steurer MA, Costello J, Baer RJ, et al. - Given that preterm infants suffer from respiratory morbidity particularly during the first year of life, researchers conducted this retrospective cohort study to explore the correlation of air quality and sociodemographic indicators on hospital admission rates for respiratory causes. All live-born preterm infants were identified in California from 2007 to 2012 in a population-based administrative data set and linked them to a data set measuring several air quality and sociodemographic indicators at the census tract level. In the first year, 5.9% (n = 12,033) of 205,178 preterm infants were admitted to the hospital for respiratory reasons. The risk ratios for hospital admission during the first year were 1.53 in relation to educational attainment and 1.23 for poverty following adjustment for confounders. Among preterm infants, California's first-year respiratory hospital admissions are associated with neighborhood socioeconomic characteristics an individual lives in.