Trends in Retinopathy of Prematurity Among Preterm Infants in California, 2012 to 2021.

Importance: The incidence of retinopathy of prematurity (ROP) has been increasing in the US since 2003. Understanding the progression of and racial disparities in ROP incidence in California can provide a contrasting perspective that may guide future research and practice in the management and prevention of ROP.

Objective: To describe how the screening and incidence of ROP among very preterm infants in California changed from January 1, 2012, to December 31, 2021.

Design, setting, and participants: This study used a cohort of very preterm infants (defined as infants born prior to 32 weeks' gestational age or weighing less than 1500 g) admitted to 60 neonatal intensive care units across California from January 1, 2012, to December 31, 2021. Among this cohort, several factors were examined, including (1) the clinical and sociodemographic covariates of the population with and without ROP, (2) trends in screening for ROP, and (3) the incidence of ROP in total and by race and ethnicity. Data analysis was performed in April 2024.

Exposures: Race and ethnicity and other birthing parental and infant descriptive characteristics.

Main outcomes and measures: Incidence rates of ROP and severe ROP. The primary measures were rates of ROP screening and incidence rates of ROP and severe ROP. Time trends in the risk of ROP and severe ROP were estimated using robust Poisson regression models.

Results: In this cohort of 39 269 very preterm infants (<32 weeks' gestational age) eligible for ROP screening, the mean (SD) infant gestational age was 28.6 (2.6) weeks. The mean (SD) birth weight was 1075 (274) g, and 48.6% of infants were female. The birthing parents of the population were 12.6% Asian, 13.3% Black, 44.9% Hispanic White or Hispanic other race, 0.7% Native American/Alaskan, 24.7% non-Hispanic White, and 1.0% Pacific Islander. From January 1, 2012, to December 31, 2021, in California, ROP screening rates remained steady at 95% or greater for eligible infants less than 30 weeks of gestational age for all race and ethnic subgroups. In this study cohort among all very preterm infants (<32 weeks' gestational age), the incidence of ROP decreased from 31% in 2012 to 29% in 2021. Incidence rates of ROP among Asian and Hispanic individuals decreased the most quickly compared to other racial and ethnic groups, narrowing disparities.

Conclusions and relevance: In this cohort study, in contrast to increasing national trends, the total incidence of and racial and ethnic disparities in ROP incidence remained steady or decreased from 2012 to 2021 in California.